Great. You should review your redirects as when trying with thebookguide.info I get a 403 forbidden rather than redirected to your preferred www domain.
Using HTTPS for that domain directly gets that error. And, for people starting at HTTP they get redirected there too
curl -i http://thebookguide.info
HTTP/1.1 301 Moved Permanently
Server: Apache/2.4.68 (Debian)
Location: https://thebookguide.info/
You should fix your DNS config for both the .info and .co.uk domains though. At least the .info if you really don't care about .co.uk
The DNSViz site is very good for checking: thebookguide.info | DNSViz
You may have inconsistent results from Let's Encrypt and well, everyone, trying to reach your .info site because of these. Similar problems exist for your .co.uk which probably explains your "Secondary" failure requesting a cert for that.
For .info pay particular attention to this DNSViz error
thebookguide.info zone:
The following NS name(s) did not resolve to address(es):
ns1.thebookguide.info, ns2.thebookguide.info
And these warnings
info to thebookguide.info: The following NS name(s) were found in the authoritative NS RRset, but not in the delegation NS RRset (i.e., in the info zone): ns1.iomart.io, ns2.iomart.io See RFC 1034, Sec. 4.2.2.
info to thebookguide.info: The following NS name(s) were found in the delegation NS RRset (i.e., in the info zone), but not in the authoritative NS RRset: ns1.thebookguide.info, ns2.thebookguide.info See RFC 1034, Sec. 4.2.2.
Many thanks again Mike. I won't be able to do much for the next couple of days but will look properly then.
I suspect that the host in the middle of its constant mergers and takeovers has quietly closed down one of the nameserver pairs I list.