Hey, I did exactly what you described, but on the PS5. It was a lucky coincidence, as I happened to have both the PS5 and PS4 versions of the game installed.
It works exactly as you said. After launching the PS4 version, I get no error on the console when listing players for sale. Successfully listing a player there also unlocks the Companion and Web App, allowing me to list players in the apps again.
The problem returns immediately after connecting to the servers on the dedicated PS5 version. After launching the PS5 game, the old error returns on the transfer market: "It is currently not possible to connect to Ultimate Team. You will now be returned to the main menu." Connecting to the servers on the PS5 version also breaks the Companion and Web App again. To be able to list players for sale, you have to go back to the PS4 version, and everything works once more.
I tried reinstalling the dedicated PS5 version, but it had no effect. I guess all we can do is wait until someone graciously decides to fix this. In the meantime, we're stuck with the hassle of listing players on the old-gen version just so we can actually play on the new-gen version.
Thanks a lot for your help. I honestly don't understand how EA's official support was unable to find any solution to this problem for over a week.
Looking at how they operate, maybe we'll get a Christmas present from them and the game will finally work correctly, because I'm not even fooling myself into thinking it will happen any sooner. I have never in my life encountered such unprofessional customer service; they should be ashamed that things like this are happening under the EA banner. I won't even comment on the fact that the EA representatives who are present on this forum have not shown the slightest bit of interest in our problem. It's simply a disgrace.
Glad it also worked for you! I have the same problem however when switching back to the new-gen version of the game; the transfer market is then once again blocked, also on the web-app and the companion app. So, for listing players, we indeed need to switch back to the old gen version every time. Very annoying. Hopefully EA will fix this transfer market bug on new-gen versions of the game soon, but like you said, maybe we'll get a Christmas present ;)
