Question Why are Environment Reflections from Procedural Skybox tinted red?

As you can see in the picture, my skybox is blue sky and green ground (the ground color is changing by script according to the time of day), but somehow Environment Reflections are seemingly assuming the ground color to be red.

I can change the Source of Environment Reflections, but it would be better to use the Skybox as is.

Is it a known behaviour and what should I do about it?

Best regards.

 

It seems that there are some directional light rotation values that are just not ok...

For example, in this test scene for X=13.95-14.02 reflections turn red, at other angles it is fine.

Sadly, at my more complicated scene red tint is present seemingly always.

UPD: At my usual scene X=50, Y=330 seems to work ok (new directional light was created like that). Any shift breaks it with red tint. Be it X=50.1, X=49.9, Y=330.1, Y=329.9, anything breaks it.
One other thing I did notice is that even compression and resolution can influence the appearance of the red tint.