Hi,

Many thanks for your help.

I'm still having trouble though.  I've removed the caching plugin, purged WP Cache & hard refreshed one of the forum pages. But still it says SEO by Yoast & the description etc is the standard meta description for that page:  https://unretired.co.uk/forum/

Here is screenshot of part of source code for:  https://unretired.co.uk/forum/pre-retirement-preparation/preparation-programme-but-not-primarily-finances/

Ok this seems to a theme issue or other plugin conflict. The screenshot is normal, ir should be there, it doesn't contain any data which may conflict. The Main SEO data are removed from that and only come with wpForo SEO. But for some reason the wpForo SEO is not there. it seems some hook is not used by your theme or some other plugin conflict with that. Try to disable  other plugins, delete the cache again and test it. If you still don't see the wpForo SEO section then try to switch the theme to some default theme for a moment, delete cache and check it.

Will do.

But did I see in the forums that some users still have issues with this WPForo / Yoast SEO etc. It is fairly usual?

All those are old topics, there is no any issue now and your issue doesn't have any relation to Yoast.

Sorted I think.

My bad! I'd set Enable wpForo SEO for Meta Titles (& Tags) to NO. They are now back at YES