I have a iPhone 5se and it won’t charge I have to power it all the way down for it to charge
How do I fix a iPhone I have to power down and yes I have dropped it in water twice and it still works
iPhone SE, iOS 14
My guess would be that the water damaged the charging circuit, your lucky it's still working at all.
You can book an appointment at a Genius Bar and have them look at it but I doubt there is anything they can do. It certainly wouldn't be cost effective to repair a phone that old.