What camera? I have 2x A119 Mini 2's and both are set to use 2K/60fps day, and night 2K 30fps. U set the HDR Timer function, on time, off time and the camera changes back to the 60fps mode during the day (HDR off).
I have had CPL on my front cam, since 2016 (a A119 V1). It never affected night image. Still use CPL at all times. It is not practical to remove it/ re install it so often.
Seen many testers vids on the various cams VIOFO makes, CPL on and off for night footage, imo, it only but helps reduce glare and reflections, even at night.
(I do not have a CPL on my rear cam, as my rear window has 50% Tint on it, that is already polarized.)
The footage you show is not at night, but dusk or still partial light out. Both non-HDR, and HDR it gonna look grainy and not ideal for that in-between conditions.
I at first, thought HDR was crap, compared to the WDR on my old cam, but was told on here, that HDR is best after dark, not when it is still light out.
See my post here:
Thought the new A119 Mini2, be the latest and greatest fancy sensor was superior with HDR and all that..... So why does it look darker, much more Nosie and just crappy compared to my old and very well used A119 V1 that has "WDR"? I also notice the A119M2 switches between this grainy noisey...
dashcamtalk.com
When enabled at the proper time, HDR, at least on the VIOFO A119 Mini 2, is TOP NOTCH!
You may also want to check the glass on the CPL, clean it (and you camera lens) with some eyeglasses lens cleaner and micro fiber cloth. Often the plastic will leave residue on it.