Oscillating value of reset pin
The STM32 has internal pull-up resistor (actually not a simple resistor). As you can see in this picture from STM32WB55CGU6 datasheet here is a preferred schematic for NRST:

Maybe the STM32 tries to control this R_pu with a MOSFET to check reset state (charge and discharge it,) so what you can do is simply remove your resistor and check if the problem goes away.
Again: you don't need an external resistor.