That does indeed do the trick!
Debouncing ISR slot is reused between certain pins. So if it is taken already it fails. Not sure if this is by design or if it is a bug. But I see the exact spot where it happens. Have to check the user guide.
An (easy?) fix would be to use external debouncing…
Probably.
It also affects Interrupt Port creation for same pins on different ports, because same 16 slots for GPIO ISRs are used.
Debouncing has not seemed to be an issue 
The latest code (thanks to Architect’s suggestion of turning off the Glitch filter) has worked 100% of the time in testing. No phantom signals to be found. I’m not sure if the STM has built-in debouncing or perhaps my awesome hardware guy threw in some debouncing when he was working on the circuit.
In any event every single one of the features now works. LED, 8 Buttons, Piezo, OLED, uSD (only problem I’ve encountered is trying to mount w/o a card present locks the system, this can be dealt w/ since we have a detect pin), Tilt Sensor and expansion ports are all 100%.
I’ll be working on code here and there on vacation…basically whenever the Mrs to be is doing her hair & makeup 
I am looking forward to seeing this in action!