Read emails in Gmail Inbox disappear, but showing in All Mail.

So this just started today (like an hour ago). When I get an email in Gmail it shows in my Inbox. If I open it to read it, and then close it, it still shows in my Inbox, but if I refresh then it disappears. Only unread emails show. If I check All Mail it shows the read emails, and shows the tag "Inbox", so they are still there, but just not visible. If I check them as unread in the All Mail view they show again in Inbox, but again, once read, they disappear. It's happening in both Chrome and Firefox. Anyone else having this issue?

I kind of figured it out (at least a fix for now). I had my Inbox sorted by "Unread first" through settings. I changed it to default, and they showed again. I changed it back to Unread first, and they still stayed. I don't know what happened, or why, but at least they are there now again.