@heavenlyrains This is the same issue my girlfriend has been having since beta. She pre-ordered the upgraded version of the game to get early access and STILL cannot access the game.
We have put tickets in, in which we get the standard response of "Try these for Ashbeard". We have tried them all and none of them work because the issue isn't actually Ashbeard, it's the fact that she has never received the prompt to link accounts. The pop-up simply does not exist for her. Her MS account is find because I bought it for her a long time ago on PC, but she doesn't like playing on PC and wanted to play on PS5. The prompt will come up when I log in, and at first I suggested she just use my profile but apparently you need PS Plus to play online (which I do not have). We tried Sony Support who said there was nothing they can do, we tried Microsoft Support who said that the only route is to contact the developer.
The most recent ticket has been open for about 2.5 weeks now, and the only responses are "We are aware and are working on it" and the canned "try the following troubleshooting methods for Ashbeard" which, infuriatingly, get sent in the same thread where they could already see it didn't work.
We were so excited to play the game, and its sad because I was holding off playing it again myself until she was able to play with me again. But it's looking more and more like the solution is only going to exist as a refund request, and she's just never going to get to play on PS5. Which sucks because if so then she won't touch the PC version out of principle, and as much as I hyped the game up, I won't be playing either.
We sail together, or not at all. With that being said, if we do hear back with a solution, I will follow up on here so you're aware as well.