Can't update User Quota - reverts back after changing to original Quota value

Cannot reproduce the problem. It is similar to Quote nextcloud reset automatic, but no conclusion was reached:

Are any of ldapQuotaAttribute or ldapQuotaDefault values set?

sudo -u apache scl enable rh-php71 -- php -dmemory_limit=512M /usr/share/nextcloud/occ ldap:show-config |grep -i quota