you'll never believe this but it's not the oil filter thing
that's the problem
the oilfilter-magic is a known thing
but in your case, the oil, when cold is too thick and clogs the oil filter
so the problem is enhanced during winter
... and goes away when the engine gets warm ...
here there's no problem with the engine cold and the light and warning comes on when the engine gets to its normal temperature...
tomorrow KTM belgium's engineer will consult with my dealer and decide what needs to be done
I'm pretty curious as to the result of their findings