ijerry

Thanks Cynthia – much appreciated – I think I can call this one resolved – many thanks!

Thanks Lisa – that’s reassuring ??

It was resolved by reinstating the REST API. Installing WP Mail SMTP plugin didn’t resolve the issue, so the problem lies elsewhere with what may be an older plugin. If the restore Legacy REST API is removed I suspect the problem will return and may need further investigation at that point.
Cheers
Jerry