Update.

[Equivz]

After my s21 powers off I am still able to power it on. 

Also swapped to 15w wireless charger to see if it still powers off.

[Glenntech]

How do you mean power off then still able to power on?
Do you mean if the phone is off and you plug in the charger it powers on?

[Equivz]

@Glentech.
I can power it on after it has powered off but I heard I could be a motherboard issue.

[Blind_Marv]

If it doesn't power on after powering off, surely you would have a dead phone !

[Egg1]

I'm guessing this follows on from your other question about charging it with a 45w charger and it turns off.
I think it's a safety feature.
The entire Samsung Galaxy S21 range charges up with a maximum power rating of 25W.

[Equivz]

Samsung says on their website about the 45w charger that it supports "Universal Compatibility" and I had no problems since I got it in January 2021