Hi @thewitch-nextdo and others.
I was doing some digging on this and found a solution for the domain issue you were experiencing.
There is a link here from Facebook which has you fill out the information where you select "I was already approved, but now I want to change my domain" and enter your new domain when asked what you need help with in the form.
Hope this helps!
I have tried using this domain change form. I received confirmation email saying I was approved with the new domain but my IG shop shows absolutely nothing different. Still cant tag products
Exact same thing happened to me. I then filled out the form to contact FB support and have told them the issue and they've been looking into it for the last 7 days. Hoping they can resolve it but had no progress so far except they've at least been replying when I ask for updates.