EDIT: I'm dumb, anybody else that stumble into this issue:

Right click taskar and select Multi-Monitor Taskbar -> Shortcuts -> Combine with Taskbar Buttons, voila, problem solved.

-----------------------------

Recently when you click a pinned item on your taskbar, the application gets another taskbar button - it doesn't collapse them.

Here is example with all 4 my pinned items open:

https://i.imgur.com/MM9LBhQ.png

It never used to do this. How can I make it behave like Windows taskbar and collapse all under one button?

Thx