Some of our UDM-Pro's auto updated to v7.4.156 and it turns out switch port profile programming has been royally screwed up in this version
All of the "default" port profiles that used to be an option (ie. one for every VLAN you've created, one called "ALL") are no longer available. Fortunately the switch ports continue to behave correctly even if you previously had some of these "default" port profiles in use. However, the moment you make a change to a port on a given switch the ports which were previously set with one of the default profiles seem to revert to the first (or lowest VLAN number) custom switch port profile.
Needless to say this can immediately cause network outages.