My 2018 Subaru Liberty's main console started malfunctioning

It sounds like the head unit and its Bluetooth functions have suffered a pretty major electronic failure. The good news is that you can replace the head unit for reasonable money these days, and get a better unit with more features into the bargain.

But before you rush out and replace the unit, try to find the reset button (often a small hole into which you poke a probe) to effect what is basically an Ctrl-Alt-Del reset. This will sometimes restore the unit to full functionality, so it’s definitely worth a try. You could also try disconnecting the car’s battery overnight to see if that resets things.