Android: Inactive tab doesn't load with web-extensions

I have the following situation:
In an extension of mine, which I only use for myself, I create two tabs. One which contains some UI and logic, and another one from a website I want to monitor.
Usually only the first tab is selected, but the second one is supposed to load and run code on load.

This worked fine before web-extensions. But now with web-extensions, It only seems to load once the tab is selected. Does anyone have an idea how to get this working?
It works perfectly fine on desktop firefox, but android waits for tab selection before it continues.

How I use it:

  • browser.tabs.create() for creation., update() for changing the url at some occasions.
  • browser.webNavigation.onDOMContentLoaded to detect load
    • browser.tabs.executeScript() to run code when the page was loaded