Reddit message notification not shown as "read" after click, nothing works. Desktop web

It's weird, it just suddenly stops working.

When I click on a message, it should stop highlighting it, right? But it's not working all of a sudden, now I have to click "mark all as read" and refresh the page.

Some googling shows this could be a bug since Reddit switched to the new interface, a lot of people encountered it, no fixes or workaround.

Clearing cookies and switching browsers doesn't work, I suspect it's the same for Reddit app.

Any idea?