I'm doing my best (for FREE) to help you.
If you would just answer the questions fully, we can get through this quite soon.
The www.richardbignell.co.uk cert was renewed Jan 30 (two days after going to CloudFlare).
See: crt.sh | www.richardbignell.co.uk
So that means, unless you have done some major changes in the configs since then, we should find some difference(s) in the two config.
[of which you have only shown one]
Again, take your time and ready through my posts and answer the questions being posed to you.
However misdirected they may seem to you.
Please and thank you.
And this statement is either incorrect/or misleading (not likely) or a forced renewal was requested and completed (highly likely) [perhaps some early testing was done after the move?]