Help needed pls - sim won't load - to do with offline mode?

Hi All

I recently dowloaded MSFS onto a brand new pc I bought specifically for it a couple of weeks ago.  

I've deliberately kept my new pc as 'clean' as possible to avoid issues/crashes, and so have only installed official MSFS updates and downloads (eg Japan and USA).

Everything has been working great (no crashes etc) and the sim has been amazing until today, when I went to load the sim this evening it wouldn't load past the US scenery page (Monument Valley I think) and a constantly spinning circle.  I tried several times but got the same each time.

At first I thought the issue might be that my internet was down (because of the constantly spinning circle) but I did several speed tests and the internet is working fine.

The only other thing that has been different is that on my last flight yesterday my internet connection must have dropped because half way through the flight it said that internet connection had been lost and it was putting the sim into offline mode.  Accordingly I was wondering if my current issue today of the sim not loading might be linked to this?

Any help advice you can give to sort this issue would be greatly appreciated !

Thanks in advance.

Paul