IME flyout window is far away from application window (DPI issue?)

Environment

Windows build number: 10.0.21331.1000 rs_prerelease arm64
Your Distribution version: Ubuntu 20.04
Your WSLG version: 0.2.13

Steps to reproduce

1. Pick up a device with HiDPI monitor without vGPU driver installed, e.g. Surface Pro X
2. Install IME package ibus, ibus-pinyin; Install random app like gedit
3. Configure ibus in IBus Preferences, confirm to start IBus daemon, add Chinese/Pinyin input method, configure IME switch key to avoid collision with Windows, keep the window open to keep IBus daemon open

4. In another WSL window, start gedit: GTK_IM_MODULE=ibus gedit
5. Switch to IME, type something, watching the IME candidate flyout window going randomly everywhere.

WSL logs:

• pulseaudio.log
• version.txt
• weston.log

Expected behavior

It should follow text in the editor as usual. For example:

Actual behavior

The IBus candidate selection flyout window goes everywhere. Also app is in 200% scale while the IME is 100%.

Reproduce on the stated HiDPI Surface Pro X setup with Ubuntu 20.04, ibus-pinyin, and gedit, then inspect weston.log, version.txt, and pulseaudio.log. Compare the candidate flyout position and scaling with the editor text position; done means the flyout follows the text and uses the expected 200% application scale.