"Save as..." window behaviour

Hi!

This might be silly question, but I’ll ask it anyway. In my work, I have to save lot of files. When I click the save as button, and the window opens it’s full screen. I prefer it this way. When saving next file the window is vertical and both the file name and “cancel” & “save” buttons are outside the screen. Of course it’s easy to click super + f to make it fullscreen and change the file name. Third file again fullscreen and so on. This is little annoying and I don’t understand what’s causing this. It’s the same thing with Firefox, Thunderbird and Libre Office.

Where do I config this? Is it window rule in bspwm or what?