iPhone SE 3-rd generation is shuting off randomly

Hey, guys, Alex here.

I got my iPhone SE3 before 5 months and the first month with the phone was amazing. It was all working out, it was fast, i can’t say a bad thing about it. But here it comes the problem- the phone started to shut off randomly, literally from nowhere. The first seconds i didn’t realize, because you know, sometimes when you turn on your phone it’s with a little delay. But no, this was not it! I tried everything to turn it on. The weird thing was that the Home Button was still going with its haptic touch, like it’s not supposed to do that. It takes hours your phone to turn on, even if it’s on the charger. The first time that situation happened i handed it to a service. A few days later, they called me and told me that the phone was turning off because of its software. They turned it to me again and the phone was in perfect condition. It’s been 5 months since I have this phone and today it made the same thing. I was going to do a Recovery mode on it, but i refused it lol. Anyway, 2 hours later my phone turned on again while it was on a charger. Keep that in mind, my phone was on 29% but when it turned on it was on 11%. So please tell me, what is the problem here?