Outlook Forms - On Prem to M365

Hi All

We are in the process of migrating our organization over to M365...mail boxes are WIP however we appear to have hit an issue whereby we have Outlook Forms (On Premise) that the sender can send but some people in the cloud cannot see the contents when it arrives on their inbox. (Note the person in the cloud can send but not receive).

We do have a ticket open with Microsoft but any pointers in the community would be useful.

Note : We cannot migrate the forms over at this point as it is linked to a huge Public Folder Migration and its kind of left us stuck