From what I've read the problem is more accurately called "uneven aging". OLED pixels age as you use them, and the speed of aging varies with brightness and other factors.I thought the LG CX's had some anti-retention trickery built in?
There's not a huge amount you can do about it. The LG's have wear-levelling programmes/patterns that you can run, but it's not guaranteed to prevent burn-in/accelerated aging.
In fact none of the OLED manufacturers will warranty a screen against burn-in. It's considered wear and tear and up to the user to prevent.