Backup process doesn't work anymore, stuck a locking the repository

So I have a backup of ~700GB on Google Drive (using rclone). But since 2 days ago backup does not work anymore. It now stops at “lock repository” (it permanently retries until it aborts). rclone and restic are both up to date. How can I fix this?

$ restic -r rclone:zombie: --verbose --password-file H:/PW --cleanup-cache backup H:/
open repository
repository 1301036c opened successfully, password is correct
lock repository
Load(<lock/22301c1fd7>, 0, 0) returned error, retrying after 720.254544ms: <lock/22301c1fd7> does not exist
Load(<lock/a59805e476>, 0, 0) returned error, retrying after 582.280027ms: <lock/a59805e476> does not exist
Load(<lock/a59805e476>, 0, 0) returned error, retrying after 703.28564ms: <lock/a59805e476> does not exist
Load(<lock/ddcd54b6f3>, 0, 0) returned error, retrying after 462.318748ms: <lock/ddcd54b6f3> does not exist
Load(<lock/b2a805d1d2>, 0, 0) returned error, retrying after 593.411537ms: <lock/b2a805d1d2> does not exist
Load(<lock/2aa34aaedd>, 0, 0) returned error, retrying after 282.818509ms: <lock/2aa34aaedd> does not exist
Load(<lock/75f3f6a181>, 0, 0) returned error, retrying after 328.259627ms: <lock/75f3f6a181> does not exist
Load(<lock/e099facd6f>, 0, 0) returned error, retrying after 298.484759ms: <lock/e099facd6f> does not exist
Load(<lock/3f12f1bd4c>, 0, 0) returned error, retrying after 400.45593ms: <lock/3f12f1bd4c> does not exist
Load(<lock/69a447f9aa>, 0, 0) returned error, retrying after 507.606314ms: <lock/69a447f9aa> does not exist
Load(<lock/17a8b50faa>, 0, 0) returned error, retrying after 656.819981ms: <lock/17a8b50faa> does not exist
Load(<lock/e15ba20c75>, 0, 0) returned error, retrying after 357.131936ms: <lock/e15ba20c75> does not exist
Load(<lock/e15ba20c75>, 0, 0) returned error, retrying after 660.492892ms: <lock/e15ba20c75> does not exist
Load(<lock/1d6570e16f>, 0, 0) returned error, retrying after 409.029087ms: <lock/1d6570e16f> does not exist
Load(<lock/6f8a2f997c>, 0, 0) returned error, retrying after 484.444922ms: <lock/6f8a2f997c> does not exist
Load(<lock/56ea07ebcc>, 0, 0) returned error, retrying after 391.517075ms: <lock/56ea07ebcc> does not exist
Load(<lock/b3f2d7294e>, 0, 0) returned error, retrying after 396.550928ms: <lock/b3f2d7294e> does not exist
Load(<lock/b3f2d7294e>, 0, 0) returned error, retrying after 884.313507ms: <lock/b3f2d7294e> does not exist
Load(<lock/b3f2d7294e>, 0, 0) returned error, retrying after 808.372184ms: <lock/b3f2d7294e> does not exist
Load(<lock/b3f2d7294e>, 0, 0) returned error, retrying after 1.186627854s: <lock/b3f2d7294e> does not exist
Load(<lock/9ecd7b64e9>, 0, 0) returned error, retrying after 430.435708ms: <lock/9ecd7b64e9> does not exist
rclone: 2019/05/15 18:40:09 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:40:09 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 535.336638ms: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:40:19 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:40:19 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 1.021868578s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:42:19 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:42:19 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 892.253525ms: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:42:41 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:42:41 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 1.345076826s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:42:49 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:42:49 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 3.170575496s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:43:43 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:43:43 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 2.682806044s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:43:48 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:43:48 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 7.776009567s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:48:13 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: couldn't list directory: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:48:13 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: couldn't list directory: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 10.223534436s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:50:26 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: couldn't list directory: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:50:26 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: couldn't list directory: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 13.11969732s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:51:19 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:51:19 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 403: Rate Limit Exceeded, rateLimitExceeded
Save(<lock/d5ed40634d>) returned error, retrying after 10.154872645s: server response unexpected: 500 Internal Server Error (500)
rclone: 2019/05/15 18:51:40 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request put error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
rclone: 2019/05/15 18:51:40 ERROR : locks/d5ed40634d5070b948da8e4ec2f5029ed22df88457effece47d08d4bbb80a53e: Post request rcat error: googleapi: Error 429: Rate Limit Exceeded, rateLimitExceeded
Fatal: unable to create lock in backend: server response unexpected: 500 Internal Server Error (500)