Maybe loosen the screws a bit. I have mine so the end of the screw is flush with the top of the nut. If the screws are protruding out of the nut you may have them too tight. I just did mine finger tight.
I have mine working as a USB HID keyboard, in Circuit Python.
Pico RGB Keypad Base support in CircuitPython - Support - Pimoroni Buccaneers
I haven’t actually programed it to send “my” key combo’s just yet though.