Found the issue with circuit breaker and GFCI outlet popping.
In a cabinet below the sink, lurks an electrical water heater - not big. call it 5 gallons or so, but it was there. Plugged into an outlet... on same circuit as the coffee machine....all quiet... so quiet everyone forgot it was there.
Super and Electrician came by and put a 20 amp outlet on a nearby circuit. Now the water heater is on its own and coffee machine is also separated.
I don’t know what electric water heater uses, but coffee machine was using 15 amps when it was the hungriest. Surely, 20 amp was not enough for the two of them.
Another mystery solved. If it wasn’t for those meddling kids...