I spent all day troubleshooting this and have found that only unprotected blogs posted after April 14th, 2020 are being populated to the Blog page. Any blogs posted before this date disappear and if I change the date to after this, they re-appear…
Same thing happened to me and I cannot figure it out. My blog disappeared and is only visible when I’m logged in as admin. If I deactivate the UM plugin, it seems to work but activating it shuts it back down. We have protected and unprotected posts on our blog. The unprotected blog should be showing up to the general audience. maxoncapitalgroup.com/blog