Can't connect PC to Steam account if the Steam::POE account already has an email address

I am trying to connect my PC account to my Steam account so I can play on the Steam deck, but get this error.

I have a PC account (A) and a Steam PoE account (B). The email address used for A and B are different. I have a single test character on account B and don't care if the account there needs to be reset or deleted. There is no option for me to remove the email account from account B.

Ultimately I want to cross play my characters from PC on the Steam deck but I am blocked on accomplishing this.