Why isn’t my SIM Card working on my iPhone XR even with new SIM slot?

Hi, I want to solve my problem. My IPhone XR got splashed in water, but everything works perfectly fine. However, it would keep on saying “No SIM.” So after that I put the SIM card in another phone (LG) while I wait for the new SIM card slot reader to come in. The SIM card worked for the other phone. Eventually, the new SIM card slot reader for my iPhone XR came in. I took out the old SIM card slot reader with the new one and then put the SIM card back in my iPhone XR. It finally worked and man was I excited. Later, after a few hours it would then say “No SIM card installed.” I was confused. So I tried the trick with toggling on and off the airplane mode but wouldn’t work. Then I tried rebooting the phone and it would work but then say “No SIM card installed” again. So then I shut off my phone and then turn it on and it would work for a few minutes then say the phrase I wish I could stop seeing…”No SIM card installed”. I shut it off for the night and next day it would work but then stop working. When it does work sometimes it would say no service which is also confusing cause I get service in my house and town. I just hope you guys can help me because my phone is all fine and has a new SIM card slot reader, but won’t stop saying “No SIM/No SIM card installed.” Can you guys please help me!!?!