Why does my mobile always go off after 2 minutes?

I have a problem with my smartphone (Huawei P9, if that matters).

It was probably a bit wet yesterday in the rain, in any case, it is now when I turn it off after about 2 minutes. The loading somehow does not always work, and when it is off and I put the cable, it goes directly to.

I put it in rice now, but I do not know if that did any good.

I would appreciate any kind of tips, thanks!

I've heard / seen that you can put it in dry rice (but before you put it in rice you should dry the phone where you can dry it everywhere) then put it in the rice, but do not do it with 5 minutes, if you should put it in rice for at least 2-3 hours or overnight. And you should (if you can) take out the battery and put it in rice (then phone and battery in the rice).

Or you leave it somewhere (in the house) overnight separated.

If it does not help then maybe it could be the battery that is not working properly anymore. (I have a cell phone which is why I do not use it any more, when I charge it to 100%, then it's off in about 5 minutes, so it's with me the battery.)

If it should be the battery, then - if you can - you could change the battery, otherwise a new one.

Switch to the battery, I've read, if the phone has NFC you have to be careful with battery, because it could be that the new battery is not NFC supported or compatible.

If really water has penetrated, "inserting into rice" is no longer enough.