With all those issues back to back, it sounds like a cache issue. Delivering old content / expired token, therefore it is caching your dynamic content and messing your admin ability. that is not likely the cache plugin. it is server side. check your hosting server side, if it is a shared host, many now have a built in cache, cdn and others. clear them all if you have access. open litespeed and litespeed enterprise are notorious about very aggressive cache, that can be disabled through your .htaccess file by adding the following:
// disable cache for admin
<IfModule LiteSpeed>
RewriteCond %{REQUEST_URI} ^/oc-admin
RewriteRule ^ - [E=Cache-Control:no-cache]
</IfModule>
// turn off the cache on the litespeed server
<IfModule LiteSpeed>
CacheDisable public /
CacheDisable private /
LiteSpeedCache off
</IfModule>
the reason i say this, because I do not think it is "refusing to turn off". it is not recognizing your authoriy as admin, due to an expired, old token, that is served from the cache, not real time. Good luck