VGA is not natively supported on the Fury X, so it is most likely the adapters or a compatibility issue. Why they suddenly stopped working is anyone's guess, and you can try other adapters DP-VGA to rule out faulty adapters. The other option is to try an older/previous driver.
I suspect if you were to test the DP connections using a DP - DP connection, they would work fine.
Yeah, I doubt it's the ports themselves, just odd that they've both worked fine for 8-9 months and both suddenly stop working at the exact same time. I have 2 new adaptors coming so hopefully it will just be those. Will try rolling back the drivers. Official support said that Windows update may have caused a compatibility issue as well, so going to try rolling that back also. I doubt it's hardware related (hopefully) with both going at the exact same time and all 3 dp ports having the same issue. To be honest I want to upgrade my monitors to dp native ones, I just don't have the money at the moment and probably won't till after my holiday and Christmas, so will probably be early next year when I get chance to upgrade, just hoping I can get all of my monitors back working before then! Lol.