Video calibration on OSMC skin - bug?

I noticed today when attempting to calibrate my TV screen, using the OSMC skin, that there were no corner markers and no “square with a diagonal line through it” when setting the pixel ratio.
I tried switching to a different skin and all functioned as expected.
So I assume this is a bug with the OSMC skin.

Please use the search function. This was discussed a lot of times aready.