Unable to edit pages or add media

I have been having issues editing anything on the website since December. Some of the issues am experiencing:

1. Unable to add media to pages. For example, I added a new member to the website fine but when trying to add their photo, the “add media” button is unresponsive. This occurs on any page where media can be added.
2. I am also trying to add speakers to an event but this button is unresponsive.
3. Editing text etc. When I am in one of our pages there is just a blank box but highlighting it reveals code not text, in the visual box. I am unable to even see the “text” view as this is also unresponsive.
4. I cannot use the arrow button to hide/show sections on pages. For example, I cannot view to edit the Hero section on pages that it isn’t already open on (plus the issues above when trying to edit things).

It appears as though the buttons on the page are all unresponsive in the dashboard. I can click on the Publish, Rewrite, etc buttons but that is it.

I have attempted the following things with no luck:

1. Clearing the cache for my browser
2. Trying a different browser (Chrome and Safari, Firefox, Edge)
3. Switching off all plugins and deactivating plugins one by one.
4. Switching to Twenty-Twenty-Three theme off the custom one.
5. I have tried the block view, this allowed me to post some “news” but does not allow me to solve any of the other issues.

None of these things have worked so far.

The page I need help with: [log in to see the link]