TdZ Stage 3 group split?

Started stage 3 (B group) with about a dozen riders, then at about 10 seconds the road split and 3 of us went right while the rest went left. I never saw the other group again (well, maybe going the other direction, but not sure). I apparently finished in 10th place. The results show 3 of us within 1 second of each other, even though I only finished with one other rider on the screen.

I had a great back and forth with the one of the other riders, so the ride was fun anyway, but curious if anyone else experienced this and/or knows why that would have happened.

thx.