So, I have this issue as well. And like you I'm pretty IT minded and tried a bunch of different solutions. I came across 2 things that struck me as interesting:
1. If I install the game on the pc of my GF, using my Steam Account, it works perfectly.
2. As a test I bought EA Play for a month since that was 1 euro or dollar, and installed WRC via the EA app. And then it also works and connect to EA servers fine.
I talked to 2 EA help employees through chat but that led nowhere.
One advice I got was to reinstall my complete PC. Yeah, not gonna do that if it worked just fine with no other alterations to my pc except for the latest update 1.9.