That’s the problem. Android’s setting options aren’t consistent, between different phones, let alone versions. The earliest phone I have runs Android 7, with no specific data save option, but my Android 8 phone has the option on the quick settings pull down tile, but not in the full settings menu, as far as I can see. My Android 7 phone though has no issue with Blokada, its been running consistently for months, until I have to restart the phone for other reasons. Even the cleaning maintenance options don’t affect Blokada.
I have the problems on Android 9 and 10, with both Blokada and Adguard. But, perhaps strangely, they will crash constantly, usually after a phone reset, then settle down after a few days, until the next cycle starts. With Adguard that interregnum can be a few days to a few weeks. Mysterious, so the app devs have my sympathy.
The other thing I’ve noticed is that another app set to always use location service, rather than the option only when using the app, seems to cause a Blokada Plus crash, maybe when both are trying to use the location service at the same time, but it might be just poor design.
I can’t see my logs showing any obvious “cause”, but I can’t find a way round the issue that when the app crashes, logging stops.