Problems using Scheduling Poll with non-Microsoft 365 recipients

- User A sends out Scheduling Polls regularly to other people at Company A.
- On those same Scheduling Polls User A also includes User B at Company B in the To field.
- Recipients at Company A are able to Vote in the Scheduling Poll.
- User B receives the email, but when they click on "Vote" it loads a Microsoft saying "Something went wrong".
- User B has an on-premises mailbox in their on-premises Exchange email server. Company B does not use Microsoft 365 hosted email.
- User B has a .onmicrosoft.com account for the subscription of his Office suite software.
- If we first sign into office.com with his onmicrosoft.com account, then try the Vote, we get a Scheduling Poll across the top but a spinner in the center. It never resolves.
- If we try the Vote URL in a private browser we get the "Something went wrong."
- Reproduced with Chrome and Microsoft Edge.

Thank you in advance,

TechJim