When i press B for showing brush popup menu at cursor position it appears on 2nd monitor instead of where my cursor is on 1st. But it shows at the same position where it could be on 1st display. BUT this issue happens when i am using stylus wacom ArtPen or standart GripPen But NOT with mouse. With mouse it shows middle of window at pointer placement how it should i guess.
Without someone who is (at least to a certain extent) a Windows user, with the expertise and willingness required to investigate these kinds of issues in depth (probably involving communicating with gtk developers) it’s kind of hard to fix them.