We never did get a fix or answer. We have a (hopefully temporary) work around.

I have changed the from email address in Preferences away from QB Email to my outlook email address. The invoice has yet another format but it is better than the terrible format with no payment link from before.

We had a generic AR email address we used to use but that stopped working from QB as well (I'm told because it is a shared mailbox but it did work before). Our preference is to use the shared email in case someone is out.

Hope that helps/