I noticed something when connecting JLink to the pad on the back. When USB is connected to XIAO, power is supplied to SAMD11. If JLink is also connected at the same time, in some cases, SAMD11 and JLink’s SWDIO and SWCLK may conflict. Do you think this is a problem? Or does SAMD11 remain in Hiz mode until CMSIS starts up as a debugger?