Migrated email content does not display correctly in Outlook for Mac

Migrated email content does not display correctly in Outlook for Mac

I'm using Outlook for Mac (version 16.11) & recently transferred emails from another provider to Zoho.

It seems that the Mac version is not able to display migrated emails correctly. All the emails are missing the subject line, and are displayed as raw message, some having first line being "This is a multipart message in MIME format" with the rest of the email body displayed as raw multipart MIME message.
All attachments on migrated messages have disappeared.

All new email messages are displayed correctly.

I have deleted and tried adding a new account a number of times even trying another suggestion of changing advanced settings to user & password.

It was suggested on another forum to change the problem emails text encoding to the Unicode (UTF-8 or 7) manually to see if that helps and it doesn't...

It appears that this has been an issue for a long time with no successful solution. I just want to have all my emails (I have several) contained within the one email program and don't want to have to change providers again.

Any workable suggestions to solve this problem would be greatly appreciated.