Triggering the reset on a person helps with every message from/to that person, and also propagates in groups. You don’t have to separately reset the group.
That’s the PNI rework that Signal recently did. I assume you see your contact by UUID, not by phone number? If that’s the case, this will be fixed in beta 11 (soon to be out there)
I assume this is the same behaviour as what @ric9k describes right above you. If so, same remark: beta 11 will fix this.