Galaxy a50 wont charge, water damage

Hello. I'm repairing galaxy a505 (A50), that was droped im water but when i dry it, the phone turned on once then the battery was dead. I replaced the battery, and the phone, when you plug the charger in, show a circle with lightning bolt but when this disappear, you can turn on the phone and everything works fine, just dont charge. So I replaced the dock flex, got a new original one, but still the same. Wont charge but if you plug the charger in when turned off, it detects the charger but wont charge. Do you think that something is wrong with motherboard connector. I clean it but still the same. The water damage is seen just near the dock flex nowhere else. Thank you, for your answers.

Thank you all for your answers. We determined,that the motherboard was damaged with water and have to replace it.