I've seen unexpected behavior on Level Extreme. Today I had two private messages, but it showed up with two private messages AND two notifications. I clicked on the notifications, and the only ones were ones I've already read from 04/23, and 04/29.

The other day I left Level Extreme running, and it seems like the longer I left it the more items would appear in the screen, like if I left it for 15 minutes, 15 minutes worth of previous posts would show up, but not from the current time, from the time when I last navigated in the page. There were no new items, but suddenly several older items were showing up.

I'm using Opera Version:58.0.3135.132 on a Windows 10 machine that's up-to-date with Windows updates.