Waterfox get minimize when running alongside Eternal Return

[ykftl]

What happened?

Issue Summary

When running Waterfox (G6) alongside the fullscreen MOBA game Eternal Return, Waterfox windows in normal mode are repeatedly and automatically minimized when switching focus or interacting with the game. However, private windows do not get minimized under the same conditions.

This behavior is specific to Waterfox. Other browsers like Firefox, Chrome, and Edge do not experience this issue when used in the same environment.

Environment

• Waterfox version: G6.5.7
• OS: Windows 10
• Game: Eternal Return (via Steam, borderless window mode)
• Hardware Acceleration: Tried both enabled and disabled
• Fullscreen Optimizations: Disabled manually (stays disabled)
• Extensions: All disabled
• Profile: Issue persists in new, clean profile
• Mode:
  • Normal window = gets minimized by Eternal Return
  • Private window = stays visible, no issue

Steps to Reproduce

1. Launch Waterfox in normal mode.
2. Start Eternal Return in fullscreen (with or without borderless mode).
3. Switch between the game and Waterfox.
4. Observe that Waterfox normal window minimizes or loses focus automatically.
5. Repeat the steps with a private window — no minimizing occurs.

Things I’ve Tried

• Disabled hardware acceleration
• Disabled fullscreen optimizations (remains disabled)
• Tested with fresh profile and safe mode
• Confirmed the issue is NOT present in private windows
• Verified other browsers are unaffected

Additional Notes

This appears to be a focus-handling or window-state issue specific to how Waterfox handles normal-mode windows when a fullscreen DirectX application is active. Since private windows are unaffected, it may be related to window flags or process separation.

Reproducible?

• I have checked that this issue cannot be reproduced on Mozilla Firefox.

Version

G6

What platform are you seeing the problem on?

Windows

Relevant log output