Those oval smudge looking things? Can I ask what you were viewing for so long that has those oval shapes in those odd areas? Were those desktop icons?
Also, as I feared, you aren't supposed to run the manual pixel refresher frequently as it wears down the TV much faster:
"WARNING! Don't perform Panel refresh more than once a year as it may affect the panel's useable life."
I know a Sony article, but uses the same LG panels.
Did you have screen shift turned on under OLED panel settings?
I'm not doubting those oval smudges could be burn-in (red especially reveals it), I'm just trying to understand what the usage scenario was like so we could all avoid it. Personally on my OLEDs, I have the taskbar set to-auto hide, no desktop items shown with a black background, screen saver set to "Mystify" at 2 minutes, screen shift set to on, and even with OLED light set to 100 I've never had image retention let alone burn-in after using my OLEDs as a computer monitor for years (desktop+gaming).
Same thing with my OLED laptop, zero issues.