Bump - this is not a platformio Question - the M5Stack hardware has been designed such that one cannot use a JTAG debugger for the esp32. as @mcbridejc states the JTAG MTMS line (GPIO14) has been used as the CS for the LCD module - all other JTAG lines are available on the M5Stack bus.
Can we request that the next revision of the HW uses a different GPIO for LCD CS?