Allow USB Accessories When Locked Doesn't Work

I have an iPhone XS Max and a Mac Mini running Mojave. I've scoured the internet looking for a solution to the fact that every time I plug my iPhone into my Mac (or to my car to use CarPlay) it will NOT connect unless I unlock it. Yes, yes I know all the security risks and blah blah blah... It's super annoying and I want to turn it off. I've gone to Settings > Face ID & Passcode and turned on the switch for USB Accessories in the Allow Access When Locked section as suggested by every web site I've gone to, but it still will not connect without a passcode. Is this a bug? Is it just MY iPhone, or just my luck?