Thank you Milind for helping me out.
I have got to item (3) and suppressed the plug ins which appeared incompatible
For item (4), please could you say where I can find the AMP page for the post, so I can add /?amp=1 at the end. Only then can I check if the issue is resolved.
It was visitors to my website who accessed my post on their mobile phones, and they alerted me to the issue of not being able to read the post.
Thanks so much.
MM
I have the same problem too…years of building up a social media presence, all gone with the migration….sigh….