MU issues: main site gets redirect loop. a doubling path in the admin and customizer for another

I’m getting a redirect loop in my main multisite site, as well as with subsite.
And when uploading images accessing admin-ajax.php is doubled. Like http://******
Saving anything hitting admin-ajax.php fails.

I have tried everything, short of reloading WP and all sites. I cleared my cookies and it started happening.

I’ve tried renaming the plugins folder, but still can’t access the site.

I think it's related to the double URL issue with wp-admin/admin-ajax.php. It’s like the url is missing the HTTP://