Curxe 3a here, so non-Pro, but yeah sometimes it’s the same as colours are all over the place, mainly in extreme oversaturation and the overall vibrancy.
I mean yeah, those photos look great but they are definitely not natural at all, and by far the most annoying issue is with skin colour because it gets to be basically orange. Then again, some other times it’s all perfectly good so… 🤷♂️ Toggling “HDR” on or off in camera settings makes no difference, same with “Auto tone”. Just take a look at my arm here and you’ll know what I mean:

That is most definitely not how my arm and skin look like, the tree in the background is certainly not viper-green either, nor my watch is THAT red, lol. HDR off, Auto tone off.
For comparison, when I use my cheap and old entry level Redmi 10C I get this, which is almost 100% accurate to how I see it all with my own eyes:

Almost 3x cheaper phone [when it was new, obviously] from 2022 snaps better photos both in sharpness and colour accuracy than the new and realistically far better 3a with NOS 3.1 🙃
So that [all the problems with the 3a camera] is all with “PHOTO” being used to snap photos. However (!), when I pick “EXPERT” all, and I mean it literally all, those problems with image post-processing are gone and photos are near damn perfect (and they look more-less identical as the second photo in this comment). Meaning that the issue is fixable if it happens with the same camera app in one case but not in the other case.