@Jonathan I’ve found this old topic about the same issue:
To be honest new server could be slower and also latencies are really reduced (new server is on premise while old one was in cloud), could be related? Or the same issue could be present in the “delete” call so move it’s executed while file was still there?
Is there any other log that could be helpful for you in case or you think everything should be solved already in 6.0.4 patch?