[macOS] App opens to "about:blankhome" after closing window without quitting

[tmercswims]

Description

On macOS, closing the last window of an application doesn't usually fully quit the application. This is also true for PWAs (since they're just Firefox), which seems to be causing an issue.

Steps to Reproduce

1. Launch PWA while it isn't already running.
2. It opens to the start page just fine.
3. Close the window, but don't quit the app completely (no cmd+Q).
4. Open the app again.
5. It opens to the URL about:blankhome

Additional Information

Demo:
https://github.com/user-attachments/assets/f94312a4-5cc7-4674-a60c-50b78e3860c7

App settings:

Profile settings:

Extension settings:

App browser settings:

While recording this demo, I also noticed that this only seems to happen when I launch/reopen the app from the taskbar. If I attempt to launch it again directly (after closing the window but not quitting) a new instance of the app starts which never fully launches, just sits in the taskbar bouncing forever. This feels like a different problem, and to be honest I don't really care about it, personally, but if you want me to file a separate issue I'd be happy to.

I've played with the "When launching a web app that is already opened" setting, but it doesn't seem to make a difference.

I've tried completely removing the app and its profile and starting fresh, and this still happens.

Lastly, this is a somewhat new thing, but it didn't start recently enough that I could even guess at a first version of anything where it started. I apologize for this, I've dragged my feet opening an issue about it 😅

Affected Websites

Affects the only app I have installed, Google Meet.

Environment

• Operating system: macOS 15.1.1
• System architecture: ARM64
• Desktop environment: N/A
• Installation method: Homebrew
• PWAsForFirefox extension version: 2.13.1
• PWAsForFirefox native version: 2.13.1
• PWAsForFirefox runtime version: 132.0.2
• Firefox version: 133.0b9 (Developer Edition)