Backends provided no user object for [deleted-user]

Large installation with LDAP backend, I have this message spamming the logs. Checking the [deleted user] in question in the db I find that an entry exists in oc_ldap_user_mapping and no entries exist in oc_accounts. The data directory still exists for these users. Full error message follows:

"user":"existing-user","app":"OC\\Files\\Filesystem","method":"PROPFIND","url":"\/remote.php\/dav\/files\/existing-user\/DataPersonal\/Documents","message":"Backends provided no user object for deleted-user"

I figured that [deleted-user] must be someone with whom [existing-user] shared files before their removal. If I run the sync command the following happens:

occ user:sync "OCA\User_LDAP\User_Proxy" -u deleted-user
If unknown users are found, what do you want to do with their accounts? (removing the account will also remove its data)
  [0] disable
  [1] remove
  [2] ask later
 > 2
Searching for username ...
Exact match for user deleted-user not found in the backend.
These accounts that are no longer available in the backend:
deleted-user, , (no longer exists in the backend)
What do you want to do with their accounts? (removing the account will also remove its data)
  [0] disable
  [1] remove
 > 1
Deleting accounts:
deleted-user, ,  (no longer exists in the backend)

After that nothing changes, the data directory for the user is still there, the error messages are still there.

Is there a solution to this?

Expected behaviour

No errors should be logged

Actual behaviour

The error in the title spams the log file.

Server configuration

Operating system:

Web server:

Database:
MySQL 10.11.6
PHP version:
7.4
ownCloud version: (see ownCloud admin page)
10.13.4.1
Updated from an older ownCloud or fresh install:
Upgraded from 10.3.2