Warning after Update sometimes

Sometimes like today after an update of my well working UCS (nextcloud, kopano, let’s encrypt) i get a warning in the system diagnostics:
Datei ‘/etc/univention/ssl/server2.mydomain.de’ hat Datei-Modus 640, 750 war erwartet.
It’s not a problem to change the modus to 750 but what is the reason for this warning and why will the modus be changed maybe after the next update?

Heiko