Godox G1 - "Connect Failed" Error

I recently decided to try out Godox gear for the first time, specifically the TT685N speedlight and XPro trigger. The new flash is in many ways a nice change after using a Nikon SB-700 for the past six and a half years. One of the reasons for that (and I might write more about the other reasons - and I might not) is that it offers firmware upgrades. In my opinion, firmware upgrades are great (especially for brands that are not high-end) because among other things they allow the manufacturer to follow up on some features of their product based on customer feedback.
Noticing that my flash had v3.0 and that v3.1 was released I was ready to upgrade it. I downloaded the software and new firmware version, only to encounter – “Connect Failed”. The annoying error was persistent and although I figured out that it was most probably caused by a missing or broken digital signature (blame Godox) I just couldn’t get a grip on a working solution. After trying the usual clean boot options and enabling and disabling different things and typing stuff in the command prompt… I finally stumbled on a real working solution posted by Michael Wlach. Hats off to him for sharing the instructions, which I'm reposting bellow.