Right sidebar widget has disappeared in all new posts

Hi there,

For some reason the right sidebar has disappeared and in all new posts on my wordpress website. It is strange, because the right sidebar shows up on all old posts, even if you go into it and make an edit on the page.

Here is an example of an old page (with sidebar):
https://www.focusedsecurity.co.uk/our-security-services/key-holding/

And here without:
https://www.focusedsecurity.co.uk/jobs-in-security/

I have tried disabling and and enabling plugins and this makes no difference.

Please can somebody help find a solution?

Many thanks