Video explaining why I think the COM port 'disappears', how I replaced CP2105 & how to possibly prevent it in the future. FTdx101D/MP, FT991/A, FT710 & FT891 all have same COM port chip and could have same issue. Warning, this should not be attempted unless you know what you are doing.
Follow up video here: https://youtu.be/3qAV5ouJpKQ
Thanks to Fred N6SMN ...
Locking the CP2105 to Prevent RF Issues via Software
1 - Download the Tool: Get the AN721SW.zip from Silicon Labs: https://www.silabs.com/documents/publ...
2 - Install USBXpress: Extract the zip, find the USBXpress installer, and install it.
3 - Connect Your Device: Plug in your Yaesu transceiver (or device with CP2105) via USB.
4 - Run USBXpress: Open the utility. It will detect your device automatically.
5 - Lock the Chip: Select the Lock Programming option and confirm. Done!