I have "Touch Key Light Duration" set to "Always On", but recently I've noticed that it is occasionally behaving as "Always Off", even though the setting is still "Always On".

Because of the intermittent nature of this problem (and the fact that it started happening a week or two ago), I'm presuming that it's a side effect of an APP that I've installed.

I'm unlikely to spend much effort tracking down the culprit, but is there some easy way to get the lights to come back on? At the moment, I go into the Display settings and turn it Off/On, but I'd welcome a simpler mechanism. Going into the settings too often is hazardous to my phone's health. Some myoclonic jerk might make a change that I can't work out how to undo...