Bitbucket Cloud - git fetch - Error while pruning removed branches

After the upgrade to 2021.1.4 (build 92954) I'm getting an error on collecting changes on my VCS repositories.

Failed to collect changes, error: Error collecting changes for VCS repository '"bones (1)" {instance id=334, parent internal id=94, parent id=StandaloneAutomatedTests_Bones1, 
description: "ssh://git@bitbucket.org/...#refs/heads/master"}'
'git fetch' command failed (repository dir: <TeamCity data dir>/system/caches/git/git-2A6EEC41.git).
stderr: Error while pruning removed branches in Repository[/BuildServer/system/caches/git/git-2A6EEC41.git]: ssh://git@bitbucket.org/...: 
remote hung up unexpectedly
remote hung up unexpectedly
elapsed time: 2s,277ms
 

I tried stopping and restarting the service, clearing the caches/git as well as agent/work and agent/temp directories, but nothing seems to make any difference.

When I test the connection in the VCS root, everything is fine.