[BUG] websites don't load on firefox and extension popup doesn't load

[z-aki]

similar bug #661

Actual Behavior

Network activity stops/ stalls and websites don't load if tampermonkey is enabled.
The tampermonkey popup shows the rotating loading GIF.

Expected Behavior

websites should load

Steps to reproduce the issue

1. Install and enable tampermonkey and use it for a while

Screenshots or Screencasts

Environment (please complete the following information)

• Browser and Version: Firefox 139.0.4 (64-bit)
• Tampermonkey version: 5.3.3
• Operating System and Version: macOS

[CATgwalker]

I have this same issue starting with FF 139 and continuing today with FF 140. Similar report in #2456.