Interesting GFCI today

1991 house, original state, no additions.
I plugged my tester into the hall bath receptacle and pushed the test button on the receptacle. It popped, but the power stayed on. Huh?
I continue to check other receptacles throughout the house and the master bedroom and dining room receptacles were all dead. Checked the panel, no breakers tripped.
OK, so I am showing the agent the bath receptacle and decide to try something. When I reset the broken GFCI in the hall bath, the receptacles in the master and dining come back on.
Report is done, referred it to a licensed electrical contractor for repair.

Does anyone have any idea what was going on here?

If the GFCI device was old then reverse wired would be my guess.