The gamma issue can be well not fixed but massaged to be less noticeable, a german guy who posts on avsforums made
a video showing how to mitigate it on SDR output with PC. His English is not great so I've copied the settings out.
This is only for SDR output.
first method
brightness = 48
side effect is black crush, this is a simple one to try if your on a PC/console.
second method uses calman calibration software and probe and has no black crush.
using settings below may not help your TV.
gamma = bt.1886
brightness = 50 (default)
white balance
IRE
25 = -2
20 = -3
15 = -4
10 = -5
7.5 = -12
5 = -11
2.5 = -4
According to him it helps with games around 60fps which raise the gamma on 120hz output. He also has
another video covering HGIG/HDR output on PC.
LG may not be able to fix this but they could add something like the above as an option to enable with VRR in picture settings, just call it VRR gamma mode.
Not everyone will see these things, there are a lot of underling variables in how games perform and the display reacts, LG's fixed 120hz gamma curve means basically the more solid 120fps or near to it the less likely you will see gamma shift.