APPLY added interface shakes up firewall

[Andreas_]

On a pair of 20.1 firewalls coupled with CARP, I have some 27 VIFs defined, total 10 interfaces.
Recently, I added two more VLANs and two interfaces. When enabling the new interfaces on the CARP master (without IP for the start), many VIFs became unresponsive after APPLY. To resolve the issue quickly, I disabled and re-enabled CARP on the master, and operation was re-established.

I'm quite sure that I could add interfaces without any problems "in the old days", but trouble increased over time (hiccup/interrupts for some seconds), now defunct VIFs. This might have several reasons:
- just a matter of many interfaces
- opnsense code to execute the interface operations was changed

Is this a known issue? Something I have to live with?