This message has no content

I keep getting the above message when Mail decides not to load email content at randon on my MacBook Air. If I check the message on my iPhone or IPad the email actually has content.

To get around this stupidity I forward the message to myself on my iPhone and presto I have an email with content in Mail on the MacBook Air.

I have done the recommended fixes I have seen on the internet - I have rebuilt the mail box; I have turned off Protect Mail Activity under Privacy and yet the same issue happens randomly again and again.

I must use the mac for my work otherwise this stupid machine goes in the bin.

Is there any permanent fix for this unreliable mail system? I am using macOS Sonoma 14.5