EDIT PAGE keeps taking me to an older version of the page

The issue is happening to me across the website, as I’ve wasted an entire day on it. Can’t seem to find anything online on the issue. Had to come to the forums for guidance.

I tried installing a new theme on the website called Neve. Since then, I’ve been facing a lot of issues which don’t make sense. In the customise option, my pages are set under the theme ‘neve’. However, in the themes section (in the Admin panel, under appearance), my theme is set as ‘Twenty Twenty’. Neve does not show anywhere. Whenever I try changing the active theme to another theme, such as Popularis, Neve pops up in the list, however, it doesn’t let me change to it.

When I leave the admin panel, and go back, Twenty Twenty is set as the active theme again…

The biggest issue I’m facing is that I can’t make consecutive edits on pages. I can edit pages, and publish them, however, whenver I go back to edit a newly published page, it does not display the new page, however, displays a very old/original version of the page.

I’m not sure what is going on, but this is all driving me crazy and I’ve wasted an entire day on this. Maybe I should revert the website back to a week old backup? Is this possible?

Thanks!

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