I am trying to: switch between visual and text editor and nothing happens when I click on the tab. If I go to a regular post or page I can switch back and forth. Also, if I do that in a regular page, the same editing mode will present on a custom post type, and I can't switch back.
Link to a page where the issue can be seen: hidden link
I expected to see: ability to switch from visual to text and vice versa by clicking the tabs (using Classic Editor)
I logged in and check the post you sent in your initial post and I was able to switch between the text and visual editor without any issues. See Screenshots.
Thanks. When I cleared the cache and tried again, I got the same result you did, i.e. the tabs worked. So the "problem" was that this page had loaded for editing during a time when I had a jquery issue. That issue is fixed, and now that I have cleared the cache, the toolset issue has gone away.