wayfire: GIMP dialog windows misbehavior on multi-headed setup

This may be difficult to describe, but let’s try. I work on a laptop with 2 external displays:

[DP-1]
layout = 0,0
mode = 1920x1080@60.000000
scale = 1.000000
transform = normal

[eDP-1]
layout = 1920,0
mode = 1920x1080@120.000000
scale = 1.000000
transform = normal

[HDMI-A-1]
layout = 3840,0
mode = 1920x1080@60.000000
scale = 1.000000
transform = normal

If I open GIMP on DP-1, it works correctly on all workspaces. The problem appears on eDP-1 and HDMI-A-1. I use the default 3x3 workspaces matrix. If I open GIMP on one of workspaces in the left column (1, 4 or 7), dialog popups are being moved to the left margin. On all other workspaces, they land somewhere off the screen. I use Waybar with the wlr/taskbar module. If I click on the button corresponding to the missing window, I’m being moved to the first left workspace in the same row.

Sample steps to reproduce:

• launch GIMP on a display which coordinates are not 0,0 and workspace 2, 3, 5, 6, 8 or 9;
• open an image
• select Image / Canvas size
• change width or height, press Center

The dialog popup disappears from the screen.