Danke! My nextcloud setup had suddenly gotten very slow after making some config changes (namely adding memcache), and I was getting another unrelated error to confuse the issue, defintiey stinks to suddenly have everything slow to a crawl for no apparent reason, but then again, it’s nice to know that protection is there, and now I know a little more about nextcloud internals. (this is 11.0.2)
I just registered to report that this bug still exists in Nextcloud 13.0.2 and that the remedy is still the same.
In my case logging in lasted over a minute, and the Linux Nextcloud client couldn’t even connect (probably because of a timeout).
You are sure it is the same bug. Check the related github issues and open a new one if you still can reproduce this error. I’m closing this (answers to such old topics mostly get no attention).