Liquid Detected in Lightning Connector - But phone did not get wet...

I have the same issue with some cables I just purchased when connected to an iPhone 11 pro max - this is the second batch of cables (9), so trying to determine where the problem exists. To confuse the matter, this problem doesn't appear when I connect this cable to an iPhone 12 pro max. Could be a iPhone 11 Pro max problem, but would think the problem would exist with the Apple manufactured cable. Could be a combination of things, or different sensitivity between phones, but don't have enough info on what is being measured. The only other piece of info that might be useful is the warning message doesn't appear right away (> 5 minutes) - so it's possible it could be a heat up issue for the monitoring circuitry.

Thought, if the connector on the iPhone 11 pro max had something on the pins/pads it could explain why the problem didn't show on the iPhone 12 Pro max, so I powered down the phone and cleaned the contacts with a small amount of alcohol on a slender swab. Let it sit for 20 minutes, and powered the phone back up. Same problem, where I get the message when the new cable is connected. Switched to one of the Apple made cables, and the problem isn't being reported.

Does anyone know whether the detection is done in the phone, or in the cable circuitry? Is it measuring leakage currents and seeing a mismatch across pins (similar scheme as ground fault detectors)?

Thanks in advance to anyone who has a piece of the information.

Note this section in this document (colored letters are links which you can click):

If you see a liquid-detection alert on your iPhone - https://support.apple.com/HT210424

"If your iPhone and Lightning accessory aren't wet

If you see this alert every time you connect a certain cable or accessory, that cable or accessory might be damaged. Contact the manufacturer.

If you see this alert every time you connect an Apple Lightning cable or accessory, contact Apple Support."