To troubleshoot this, I disabled the Profile and imported a Profile from another working website. That made no difference.
I also disabled JCH Optimize Pro plugin, and checked if there were any errors in the web dev Console. That didn't reveal anything.
I saw on another forum post it was suggested to disable compression of CSS and Javascript, but those are already disabled.
I tried installing JCE Pro 2.7.14 again but nothing changed.
See this demonstration video = https://cl.ly/ba2faf160354
I'm at a loss on what to try next. Any suggestions?
Thanks,
Richard