I use duplicati to run backups. Duplicati keeps after a certain amount of backups says server is locked, 423 code. Acording to duplicati this is nextcloud issue. I have tried for months to get assistance and I can not. So now I am willing to pay someone to fix this.
I run fluently backups on my own installed nextcloud + db with duplicati. Email me ww (at) iki.fi and lets continue there.