catalina 10.16.6 Mail

I have a MacBook Air mid 2015 13" on Catalina 10.15.6. Inconsistently, the mail app will not download photos or graphics on any of my devices: MacBook Air, iPhone XS Max, iPad Air 10". The email looks as though it has no content. Nothing I have done has corrected the situation including 1. closing and re-opening the email, the mail app, 2. clicking all over the email... 3. forwarding the email to myself, 4. viewing it online if there is a link and 5. checking that my preferences are set up correctly for viewing attached graphics (they are and have been)

I have found no working solutions that I haven't already tried.... Does anyone at APPLE have any suggestions, work arounds, corrections, anything???? ?????