Just for an update - I had a response from PlayStation Support on the 4th Jan 2023 stating that because I had completed the troubleshooting checklist (uninstall and reinstall - as if!) they would refund me.
So this probably makes sense why it's off the PSN store, since I saw there was no Digital version. I collect the physical regardless since I have been buying all WRC games to play them in order, and tonight i tried 8, and wow....it's lighting system is literally broken and unplayable. So this is a PS5 issue? I notice when I started the game it said "this game might not work properly on PS5"
Good luck Clauss! I had to follow a 'mandatory troubleshooting guide', send screenshots and then finally this video. And each time I had to wait almost an hour on their online chat! Maybe providing them with the URL of this video might speed things up.