@bethemwithoutapology You most likely turned on a timeline filter and forgot to turn it off. Look at the Search icon in the top right corner of a timeline view and if you see a small circle in it, you have an active filter on and it is hiding posts that don't match.
@ivory Geez, I was about to write to you about why I was missing posts but I thought twice "someone else must have the problem" and sure enough... Must have turned it on when I was just poking all the buttons to see what they do.