That vertical banding is pretty wide. Maybe the T-Con board?
Anyway, that pronounced narrow purple/red line smack in the middle of the banding looks just like the line I had on my LG.
In my case, it was TAB bond failure. (Solderless connection of a data ribbon cable to the panel). I took the bezel off and gently pressed each ribbon cable with the butt end of a screwdriver and found the one with the bad bond. (The vertical line will either disappear or get wider). I rolled up a bit of electrical tape to make a cushion and put it behind the point where the cable connects with the panel, in a slight recess there. When I put the bezel back on, the bezel was no longer pushing the cable out of alignment.
While the above is not really a "fix", but more of a "band-aid", the TV in question has been fine now for 9 months.