Yes, I did read through the help post, thanks. I will try reinstalling the game again, but I'm not sure about the different stages? I delete, restart, immediately prompted to update, and then asked if I'd like to install files on the HDD. Are these points where youre saying to check for issues?
Right. You can stop after each update, to check as you go along. You just have to cancel the next one.
When you do this, take your current profile out of the equation. Copy it somewhere safe before you start, such as onto a USB memory-stick. So long as GT does what you expect, continue to the next update. At some point, you either find a fault or you are done and everything works. If you then re-install your old profile, it will either work or not.
Welp, a call to SCEA has done no good. They had no idea what the issue could be, suspected it was on the developers end and their servers, but could not provide me a number to contact them, which is odd.
I tried finding a number for Polyphony Digitial (still not even convinced I should be calling them anyway), but I haven't found one.
Back to the SCEA service - they were stumped. Had no options to even try.
Have you tried connecting directly to the modem? That could possibly narrow down where the problem is occurring.