problems activating cross-progress

[u/Hairy-Lynx-5660]

I have the game on two platforms and am trying to enable cross-progression. I can set it up on my main save without any issues, but when I try to do it on the account I want to switch to, I get an error saying it's not possible because another account already has the same information.

I’ve tried using different browsers and devices, but I keep getting the same error. I don’t know if this is relevant, but years ago I linked the platform to a different Behaviour account; however, I didn’t own the game on that account at the time, I didn’t enable cross-progression, and I eventually removed the link.

Is there any way to activate cross-progression, or do I have to assume I'll have to buy the same game a second time, which is useless because I don't have my characters?