With great imagine I found, that my articles are accessible from any URL which contains Article ID. Live example is here https://moskovskiykvartal.ru/catalog/sell/flats/168. This is a real URL of realty object. Sorry - it's in Russian, but it doesn't metter for our problem. You can see canonical tag - it's the same.
Of cource I can code in my override template to go to canonical URL - but this is wrong, isn't it? As I know - router was changed in J!3.8.0 - maybe, this is reason?
this is how it always was in Seblod, with all different possible url creation options it would be to complex to allow only real urls, this is why only last segment is used.