It’s hard to say. It happens sometimes during development, i think specially when webpack recreate all static js and css files and i have development reload enabled on manifest.json
What i’ve seen since last update, the 155, in these moments the background controller hangs on developer tools and i have to disable\enable the application (or close from task manager) to recover it.
Unfortunately, without a sample app and exact steps to reproduce, I can’t progress with it, as I’m not familiar with it. Till you have this info, I would recommend asking the community in the tech_questions slack channel. Maybe someone suffered from the same issue.
I will tag @tom.wolf here, just in case he came across it.
I think it’s definitely when you’re loading an unpacked app, and the app crashed on load.
Then when you fix whatever made it crash, you disable/enable the app in Packages, and then open the app again, the second entry in the tray appears.
I’d say it’s extremely low prio to fix this.
It doesn’t really harm anyone, and as it only seems to happen with unpacked apps, it won’t be an issue for the end users.