So here I am trying to paint an environment and deciding to change some brush settings and boom there is a gaint brush preferences window smiling at me.
Well I can just send resize it, but it takes at leat 30 seconds until it refreshes this window.
Is there a bug report about this already?
The resizing starts at 3rd second in case you do not see my interaction. The rest is wait for a response
Did you try to disable all your imported plugins first? I’m asking, because it can be a malfunctioning plugin.
For me, if ever, this oversized representation of Krita’s Window or dialogs of Krita only happen once directly with the first start after a fresh installation of Krita or the OS (I’m using the portable versions of Krita). After my first resizing of Krita, this does not happen again.
Michelist
As I tagged the topic, I am showing a recording of my android tablet screen. There are, as you know, no
plugins available on android. 
Yes there is a bug report about it https://bugs.kde.org/show_bug.cgi?id=523346
Can’t reproduce it.
LOL, I guess I fell into a trap of my own making. Since I’m familiar with the problem in a different context, I didn’t even notice your tag anymore.
Michelist
What can I do to help?
If you can find steps to take to reproduce this issue, that would help a lot. You can try to install the Krita Plus nightly build, which Android treats as a separate “Krita Next” application and starts you from a blank slate. If you can find a way to make the problem happen there that I could make happen as well, I’d say it’s pretty likely I could fix or work around it.
Is this for all brushes or is it a particular brush or two? For me, I’ve noticed a few do this, not all of them. 
Well it is sporadically appearing. Here I tried to modify the leaves stamp. But it doesn’t have to be that way … Maybe it happened after I imported a bundle? 
But you should not undock the preference window with that little checkbox at the bottom right. Then you have no possibility to move or resize the window.