Yes that happen now and then with different systems, but the reason are simple, your 2 cameras are not the same sensor and so one might be more sensitive than the other.
I dont think the different brands do anything to mitigate this difference, in your case the sensors are probably the same physical size, but as your front camera are 4K they have to cram in many more pixels on the same area, and the only way to do that is to make the pixels smaller, and so also less sensitive to light.
It is sort of the same you see some phone cameras do with their night photo mode, so in that case they " cheat" a little and bin up pixels from the sensor, so your 64 mpix sensor will suddenly only shoot 12 mpix night photos CUZ it bin 4 pixels into one pixel to that way make a virtual pixel that are 4 X more light sensitive.
Sadly we have not yet seen pixel binning in any dashcams, but in theory a 8 mpix sensor ( 4K ) like in your front camera, it could be binned 4 to 1 to get a much more light sensitive virtual 1080p camera,,,,,,,, which would be fine for parking guard.
But binning are not a option in the SOC that are used in dashcams these days.
8 megapixel / a little over that are what it take to make true 4K footage. Some phone cameras will do that too without binning pixels but then from your 64 megapixel or larger main sensor, but in that case only a part of the sensor are then actually used ( crop )
