Tasker: Android System Power Management
Android System Power Management
Starting with Android 5.0, many devices will act aggressively to try and
save system battery power. Unless certain steps are taken, Tasker may
not function as expected, either because Android is not sending it the
needed signals in order to save power or because Android is even killing
Tasker.
A commonly noticed symptom is that profiles with Time contexts don't activate
or deactivate at the expected time.
Make Sure Tasker Is Not Killed By The OS
Making sure that Tasker is not killed by the system can be tricky because of all the restrictions Android applies to background apps, but in the majority of cases it's possible to do.
Please go through the list here for Tasker specific settings.
Also make sure to check out this page for vendor specific procedures: dontkillmyapp.com