It looks like Google made a change to the Webview with the Chrome 98 update, and suddenly all apps are showing in Dark mode (even if the user did not choose dark mode). We’re seeing this happen on the second launching of the app, not the first after install.
It looks like they possibly changed something in prefers-color-scheme support, some more info here: Installed app suddenly becomes dark - Ionic Framework - Ionic Forum
Is there a workaround that still allows to use autoDarkTheme?
We also have this issue! I don’t think it is related to Framework7 itself.
In our case, we use the cordova qr scanner plugin. Normally, we set transparent background color on body and f7 app container when the qr scanner is started, so the camera view behind the html is visible. But now, when the user has the body background is somehow overridden with black and the camera view is invisible.
So altough we don’t declare dark theme support through media query, Android decides to put black background on random div containers on it’s own… 
This behavoir seems dependant of the phone’s brand. My Samsung test device does work as expected, but a customer with a Xiaomi 8 has this problem.