Q10 Aspect ratio problem playing 4k file on LG oled

[Lavalyte]

When I play a UHD .mkv file on my OLED LG TV, it's distorting the picture and ignoring the file's aspect ratio.
I would like to either zoom in slightly and cut off the sides of the panorama aspect or have black bars below and above to keep the aspect ratio correct.

Does anyone else have this problem?

[unclejoshc]

I have an LG C6 OLED and I have not had any issue with aspect ratios.  Is it happening to all files or only a specific one?  If it is only one then it is an issue with that file not the device or the TV.

[Lavalyte]

It's happened with two UHD mkvs so far. I don't have any other UHD files at the moment.
This doesn't happen with HD files.

[Lavalyte]

I should say, the PVR is set to explicitly maintain aspect ratio.

[Mount81]

While you see the Box's "picture" on the TV set the aspect ratio on the TV to 16:9 or -more likely- to "Fit to Screen", or search something similar in th menu.