Not exactly sure what's going on here, but you might have better luck breaking up your collision polygon into multiple simpler objects. Collisions with complex concave shapes have a reputation for having issues. In general you probably want to avoid having such a large sprite object to begin with.
Solved the problem: initially the sprite was 13000 pi. Divided the track into equal parts in Photoshop, up to 4000 pixels. I added physics and a collision mask to each sprite. During testing, it is processed normally.
Thank you for answering.
By the way, I made a tile background with the same collision polygon - physics was not processed anyway.