Since upgrading to Sonoma, Apple Mail is displaying some styled email body copy with ???

I updated to Sonoma a couple of days ago, but now on a number of formatted emails from different people at different companies, using different email service, that I am receiving - the body copy is showing up as ???? rather than content and the only way I can read the emails is to reply, highlight the text and then from the contextual menu click, remove styling, and then I can read what they had written.

What has happened and how can I fix it, without having to give up on Apple mail?