I am installing Nicla Sense Me as shiled on Portenta h7. when i press reset button on board or using NVM_reset function or even using WatchDog timer, the H7 board not boot again,until i remove Nicla board from H7.
Also i have mentioned
that when restart happen, the board not recognize by Arduino IDE, until i remove USB-C and plug-in it again.
I followed this link for plug the Nicla on top H7 for pins and the communication between board is OK and every thing is working great.
the portanta H7 runs on MbedOS but its port was done and is maintened by Arduino.
Arduino has fork of MbedOS and also ArduinoCore-mbed where they apply their own patch for MbedOS. So my recommendation is to visit Arduino web sides and their repos.
The reset button is usually connected to MCU reset pin so if the reset is not working, then it looks like the shield blocks the reset pin from its functionality.