An unsolvable layout problem, is it possible?

Question

Layout

Good evening, that’s what an unsolvable problem happened, which I couldn’t google. There is a certain slider in the layout with a cut corner (under a spoiler), that's fine, 1000 + 1 way how to do it is described here, BUT there is still a stroke that crawls out of the cut corner when layout (under a different spoiler), and it's okay cropping fails. Who is responsible for such tasks?

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