Re: PIC16F18855 PPS problem
Multiple peripherals can input from the same pin simultaneously, so input PPS registers are by peripheral, so RXPPS (or INTPPS or SSP1CLKPPS, etc.) are assigned the pin code.
An output pin can only come from one peripheral, so the PPS register are by pin, so RxxPPS = peripheral function code.
Note that outputs never have default assignments, but inputs do. I do not rely on defaults and always assign both input and output PPS even if I happen to be using the "default"