What activated USB-C water intrusion alarm feature.
"Liquid Detected in USB-C Connector" alarm went off on my 6-month old iPhone 16 Pro (IOS 26.2) when attempting to plug a USB-C charging cable into the USB-C port. I could not access the phone when alarm going on and the lock screen displayed "emergency". I tried several USB-C cables and all of them set off the alarm. My first inclination was that the recent IOS26.2 was at fault and somehow interfered with the phone's "emergency" circuitry.
The problem only started simultaneously the first time when I mounted the phone sideways to the tripod clamping feature. Thereafter, I slide the phone to the very end of the phone away from the buttons. Days later I took more pictures using the same end mount process. I thought no obvious issues. But later when I tried connecting the USB-C cable to charge port the alarm went off. It was NOT a faulty cable issue. By chance, I found that the charging problem went away when I removed the official apple protective case. Could the spring loaded pressure clamp on the tripod have somehow activated the internal alarm system or damaged something inside the phone. The phone is now charging fine after putting the phone back in the case. As a a precaution I depressed case button indentations from inside-out to insure the side buttons were not depressed. Lastly my USB-C port was not full of lint. the phone was not exposed to moisture and humidity was low.
iPhone 16 Pro, iOS 26
