In settings there is a checkbox that is labeled “show read posts.” If that’s not checked, any post you look at while logged in will be hidden after you reload the page. Note that this includes even your own posts!

I suspect you’ve cleared that checkbox.

I am having similar issues with other pages ive subbed to. Im only able to access like one or to posts and i think i have all appropriate boxes checked. I wish there was a diagnostic windw for this kinda thing