Before re-installing firmware, I would try a 'clear config' (under expert settings).
That will help reset internal parameters, in case something amiss there is affecting this.
Regarding new firmware, when you put the nanovna in DFU mode, it will remove the com port, and a new entry will appear in device manager under the 'Universal Serial Bus Controllers' or 'Universal Serial Bus Devices'. It will either be titled "STM Device in DFU Mode" or "STM BOOTLOADER".
If it says "STM BOOTLOADER", use STM32CubeProgrammer to update the firmware.
If it says "STM Device in DFU Mode", use nanovna-app or DfuseDemo to update the firmware.
Otherwise it won't connect. Unfortunately the drivers are not the same for the different applications.
Stan KC7XE
