Similar issue here too: Unable to log in to MS services after failed update attempts - #4 by MTpiperpilot
same problem here. After the UK-update the sim doesn’t load and hangs .Phoned microsoft and went through all settings. They thought its my video-card [ Radion RX-580 ] I know this is not a fast card but worked fine for me till the UK-update.Had Wib10 and MSFS20 freshly installed on a new SSD 1TB.
What to do? 
Luckily I still have my FSX but it’s frustrating considering what FS2020 is able to show.