RTK base with a Raspberry pi4 and SimpleRTK2B

What do you mean “unresponsive” ? If you mean there are no satellites shown anymore, that’s normal : this data comes from NMEA messages, which you disabled.

However, there is a risk that your board becomes “bricked”, which means because you disabled too much communication protocols, you can’t access the F9P anymore with U-center. It may be what happens. Though, you probably didn’t send the modifications to the F9P to make them permanent (explained here, step 4). I never bricked my F9P, so I can’t tell much more though