Hi,
>>The only way I could get it to work was by typing out the address from the person who'd sent it to me rather than linking it to the contact in my personal contacts.
Do you mean select names from Contacts shown as the following picture?

In that case, according to my test and research, if you want to choose directly from Contact, you may need to make sure the contact display name exactly match the full name that appears on messages that you receive. If display name is different, please change
the contact information and then check the result.
Hope this is helpful to you.
Regards,
Perry
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