Can you check what user group he has been added to? (check this link if you don't know how to see usergroup)
If it's different to the user who can edit the pages (as on page editing), then you can add to same usergroup. Please let me know if that don't work.
Does the user have any errors in the browser console?
Is it possible for the editor with the problem, to test the computer/browser of an editor without the problem.
Would be nice to rule out anything other than the user account.
Sounds like it could be an issue on the users local machine.
Ask them to do the following:
To rule out a server-side problem with the user, perhaps you could try resetting their password and logging into their account yourself to see if you can replicate it.
Maybe worth checking if the user has an browser extensions installed that be interferring with the UI
Definitely check other browsers and incognito mode if using chromium. Plugins can absolutely interfere with websites and often do. I once had a Tealium debugger plugin that prevented Google SSO from working.
Also check the user's network traffic to make sure nothing is blocked- make sure they have nothing in their hosts file redirecting traffic, etc.
We have an issue where one editor can not use On-page edit to edit pages, they have however no problem editing if they switch to the all properties view. If they switch to on-page edit the page renders as it does for visitors or in preview, without the blue borders around fields and content does not become editable when clicking on it.
Here is what we have figured out about this issue and what we tried:
The site is using EPiServer.CMS 11.12.0 and EPiServer.CMS.UI 11.20.1
Have anyone seen a problem like this before or have any suggestions on what we can try so the editor can use on-page edit?