There are some fixes available… all are discussed in this article.

Hope this helps. Please let us know.

I have tried:-
Solution 1: Confirm the HTTP Error
Solution 2: Switch Browsers
Solution 3: Deactivate Plugins
Solution 4: Increase WordPress Memory Limit (took copy first)
Solution 8: Check Your PHP Version (7.2)
Solution 9: Clear Your Caches

with no fix, I’m reluctant to do the others as it’s out of my area of expertise, the risks are too great.

I’m prepared to live with it, thanks