This is a bug that I think may be addressed in the next update, if I’m reading the commit history correctly. Couldn’t tell you when it’ll be released, but I’d wager within the next couple days.

I’ve used the app for over a year and a half, for me it always takes a bit for new messages to load. Give it a second and I’d bet they’ll be there.

Same for me

Does it go away when you click the “mark all as read” button at the top?

I have also experienced this.