[fandangos]

Is your shield running the latest firmware?

It got automatic color space switching a few firmwares back.
You can enable and disable it.

.ts should not work since it uses dual layer dolby vision and this is not supported.

Yes, running the latest. The auto colour switching doesn't work, according to the TV HDMI service info menu when the Shield is set to Rec2020 DV and HDR10 Ready, regardless if auto-switching is enabled. It will only auto-switch between the profiles if Rec709 DV and HDR10 Ready is selected.
This is off-topic, of course, but interesting find. If you have an LG TV, I can explain how to test that.

p.s. - kodi 18.9 is using a lower version for the backup addon than kodi 19.0. I cannot restore due to some error which I have no idea about.

If you are talking abour the '111111' hidden menue, the menue is buggy and does not always display the correct color space information, especially for DV. The shield is tunneling DV in an 8Bit RGB tunnel and this is confusing for the menue and can cause bugs to display wrong information.

The Shield shows DV as YCbCr 4:2:2 when you activate Dolby Vision and I believe it might need 10bit/12bit the same as HDR (10bits).

I can check with my receiver and the LG menu later today.