Winbind, what can cause corruption of cache?

I have a "working" Samba4 enviroment. I use the old good method of Winbind, works fine but sometimes(after Samba upgrade version for example) the cache become "corrupt" and my user disappear. wbinfo -i pinuser failed to call wbcGetpwnam: WBC_ERR_DOMAIN_NOT_FOUND Could not get info for user pinuser If I delete the cache files the user magically appear find /var/lib/samba/ /var/cache/samba/ -name gencache.tdb -exec rm -vf {} \; systemctl restart winbind.service wbinfo -i pinuser pinuser:*:10005:10016::/home/pinuser:/bin/bash What can cause the cache corruption?