Mostly works well on Windows 11, until your computer goes to sleep. After you wake it up, Firefox has no Internet connectivity until you close and reopen Firefox, or disable the Proton VPN extension.

Developer response:
"Sorry to hear that. Could you share more details about the issue? What version of Firefox do you currently have installed? Are you receiving any error messages after waking the device from sleep? Are you using any other extensions for privacy/security purposes? Contact us at [support form URL] with more details so we can investigate the behavior further."

My response to developer:
I filed a support request with details last week and haven't heard anything. I'm disappointed to see a response to my review here before getting a response from support. But since I'm getting a response here:

Windows 11 23H2 build 22631.4460
Firefox 132.0.2
Proton VPN 1.2.3
No error messages (unless I open up the Browser Console)
Other extensions in use include uBlock Origin and DuckDuckGo Privacy Essentials.

The problem immediately goes away when I disable Proton VPN after waking from sleep. I can quickly toggle the extension off and back on and Proton reconnects and everything works from that point.