Back tap function not working on my iPhone

Cases are a definite issue as Rudegar points out. I don’t use a case and the two tap and three tap work about 90% of the time. I’ve also found it works best when tapping near the Apple logo on the back.

Rudegar wrote:

it works for me like 1 in 5 times, suppose it's my timing with added it being in a thick case that works against me

I had the reverse problem. I was constantly triggering it when I didn't mean to. And that's with a case.

it works for me like 1 in 5 times, suppose it's my timing with added it being in a thick case that works against me

Same here. I've given up on it because it rarely works for me. Case doesn't make a difference.