Hi,
Sometimes the Seeeduino XIAO port may disappear when user programming process fails. we can solve this problem by the following operation:
[list]
At this point, the chip enters Bootloader mode and the burning port appears again. Because the samd21 chip has two partitions, one is the Bootloader and the other is the user program. The product will burn a bootloader code in the system memory when it leaves the factory. We can switch modes with a quick reset.
[attachment=0]XIAO-reset.gif[/attachment]
So Can you try to use the
[attachment=1]Seeeduino XIAO pinout 2.png[/attachment]
try the VIN pin and let us know the feedback, also please comment on your solution of the last question so it may help other people too :).