@Abel I uninstalled the device in Device Manager, and rescanned. Behavior doesn't change. Device Manager quitting is very strange, and i suspect a very deep error. Reinstalling the OS is not an option. I have surrendered, and bought a new laptop for this project.

@Abel I tried swapping boards and ports, all read COM1. I'm not sure if that's what you meant. If not, please clarify.

@Majenko I don't see a property called "serial number". I'm looking in the dropdown menu of device manager tab Details/Property. Trying two boards, the Location is Port_#0002.Hub_#0005 and Port_#0003.Hub_#0005. The is also a property called "Device Instance Path" that is for one of them "USB\VID_2341&PID_0043\95036303235351312061" and they are different.