Flashing Brake Light - CX5 2018

Hi everyone, I got a 2018 Mazda CX-5 f4om a non-Mazda dealer yesterday and I’m having an issue with the electronic parking brake (EPB).

When I pull up the parking brake switch:

- I can hear/feel the rear parking brake motors engaging

- The vehicle seems to be held by the parking brake

- The parking brake button light and brake warning lights start flashing

- Orange P on dashboard

I tried:

- Holding the EPB switch up for a few seconds

- Releasing and reapplying with the brake pedal pressed

- EPB maintenance mode/reset procedure

No luck.

The brake seems mechanically engaged, but the car does not recognize it as fully engaged.

Has anyone experienced this on a 2018 CX-5? Could this be a low battery issue, EPB calibration issue, brake switch sensor, or does it require scanning the ABS/EPB module for codes?

Thanks!