@FieldGunner @bam12208834 I got my issue fixed after scouring these forums for anybody experiencing the same thing or something similar.
I am linking the post which ultimately worked for me here, but I will also include the text of what I did for posterity and the next person to experience this issue digging through the forums 5 years from now.
Essentially, the issue for me was caused by my cloud profile being corrupted somehow. Unfortunately there is no way to simply delete your cloud profile from within MSFS, so you have to brute-force it by doing the following:
- Load MSFS as usual
- While on the loading screen (“Checking for Updates”) pull your Ethernet cable or Wi-Fi router if you’re using a wireless connection.
- MSFS might take a moment or two to figure things out and will then prompt you to install an “update” - a file only several kilobytes in size. This is a new local profile that the game creates in place of the cloud profile it can now no longer access.
- Once on the main menu, close MSFS.
- Re-connect your ethernet/Wi-Fi
- Launch MSFS again
On launching MSFS for the second time, the local profile is no longer required as the game realises you now have an internet connection. Therefore it creates a brand-new cloud profile for you. This, for me at least, then meant I could load into a flight with online functionality turned on as normal, and the sim has performed normally for the last 2 days since I fixed this.
Hope you guys find this useful and get your sims fixed!