Not a valid JSON response

I am using WordPress and WP Recipe Maker for a recipe website. I haven’t been able to update any of my Posts – I click on the recipe, get the message, click within the block i wish to modify, and it hangs on ‘Loading Recipe’. Eventually and error pops up: Updating failed. You are probably offline.

Upon further review, it appears it’s because of an invalid JSON response. I have deactivated all other plugins, changed, themes, installed classic editor, disabled Gutenberg, activated Health Check & Troubleshooting (no issues – green), completed the PHP Compatibility checker (all ok). I’ve also tried changing permalinks from Plain, to Post name, back to Plain. Nothing has worked so far.

The blog posts suggests a URL problem. So on my WordPress site settings I have these:
WordPress Address (URL)
https://clavijo.site.nfoservers.com/Wordpress
Site Address (URL)
https://www.tastyfamilymeals.com
Enter the address here if you want your site home page to be different from your WordPress installation directory.

When I type the top one in a search bar, i get Epic 404 – Article Not Found. This could be my issue. I changed it to: https://clavijo.site.nfoservers.com/Wordpress/wp-admin/, however, that completely booted me out of wordpress and i had to have by database restored by NFO. So… I’m back to square one. Any help is appreciated!

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