[Linux][Chromium] mousemove to out of the window left or top with mousedown, X or Y coords get 65536.

Chromium-based browsers on my Ubuntu, mousemove to out of the window left or top with mousedown, X coordinate or Y coordinate are large value(s) close to 65536.

Is there anyone in the same situation? Tell me how to solve it.

screen record

Occurrence condition

1. Mousedown on content area (No logging without mousedown @ to out of the window)
2. To out of the window left or top (No problems @ to right or bottom)

Results

Chromium run with "--disable-extensions"

Abnormal (get large value)

• Chromium 86.0.4240.183 snap (on Ubuntu 20.04)
• Chromium 86.0.4240.111 snap (on Ubuntu 20.04)
• Chromium 86.0.4240.75 (on Ubuntu 18.04)
• Microsoft Edge 88.0.680.1 dev (on Ubuntu 18.04)

Normal (get valid value)

• Firefox 82.0.2 snap (on Ubuntu 20.04)
• Firefox 82.0 snap (on Ubuntu 20.04)
• Firefox 82.0.2 (on Ubuntu 18.04)
• Firefox 82.0 (on Ubuntu 18.04)
• Chrome 86.0.4240.183 (on Windows 10)
• Chrome 86.0.4240.111 (on Windows 10)

Checked environment

• Ubuntu 20.04.1 (64 bit)
  • LXQt
• Ubuntu 18.04.5 (64 bit)
  • LXDE
  • KDE

Verification

verification site

verification code

or simply

addEventListener('mousemove', console.log)