Second monitor not as bright as main screen - totally stumped

I have 2 external monitors and they are both significantly less bright than my main laptop screens. Screens plural because I have 2 separate laptops (one HP and one Dell) with 2 different graphics cards but both the same issue connected via VGA to said monitors. The VGA cable has been eliminated as the culprit as well.
I have gone through every setting in Win 10 I can find and there don't seem to be any more to try. I've updated the drivers for both monitors and the NVIDIA graphics card on this PC but the other has Intel graphics built in. I have even changed the display adapter to the generic Microsoft adapter but all that did was make the second monitor disappear as Win 10 could no longer detect it no matter what I tried.
Of course I've already tried the monitors' own brightness etc. levels and then using graphics card to control color levels to no avail. I'm stumped. The only thing I haven't tried is calibrating them but I'm almost certain that won't help either. That seems to be for fine tuning colors and such and this problem is much more pronounced than fine tuning.
It's almost as if the external monitors are running on battery brightness settings but I don't even have that as an option in my power profile settings.
My HP laptop was previously hooked up to an Asus external display a few years ago, by VGA, and it looked fantastic - even brighter and more vivid than the crappy HP screen which is very listless and dull in general. I used the old Asus monitor without issue with the HP's original Windows 7 and also after I upgraded it to Win 10. Makes me suspicious that a more recent Win 10 update is the cause but I have no idea. Both laptops are up to date and I think I'd find more people out there reporting similar issues but I've found next to none.
I feel like it's something fairly simple I'm overlooking. Any help will be greatly appreciated.

First PC:

HP Notebook 2000 363nr
i3 370m
8 gigs ram
Intel graphics built in
Windows 10 home

2nd PC:
HP Precision M4500
i7 620m
NVIDIA Quadro FX 1800
8 gigs ram
Windows 10 home

Monitors:

Asus X223W

Dell E2010Ht

- - - Updated - - -

Microsoft claims this is unrelated to OS and you should either consult your monitors customer services or try to update or downgrade your graphics drivers .
https://answers.microsoft.com/en-us/windows/forum/all/dual-monitors-the-second-monitor-is-very-dim/d1d68465-6d81-4403-a694-bc8b73d478ff

Further more you can check non of your monitors has a setting that does such thing such as "Adaptive contrast" or your laptop has the setting "Adaptive brightness" enabled .
Adaptive Brightness | IT Services

Thank you nIGHTmAYOR. I think I've tried all the settings to be found on both monitors but I'll keep looking. It does feel like an adaptive display-type issue. My laptops do not have light sensors so they don't have those options but the degree of dimness I'm seeing looks exactly like what you would expect from a Windows or monitor setting of that nature.