Thanks! This is what I understood from reading the 2e rules, putting some emphasis on the similarities and differences among editions, in case it may help to detect if clarification is needed:
1) both 1e and 2e: choose the dice to roll
2) both 1e and 2e: roll all 4 dice
3) bothe 1e and 2e: apply abilities to reroll or modify a dice
4) both 1e and 2e: detect which one has the top value among all of them (2e doesnt say if its the top value on each side, i.e. the top of the active dice and the top of the opposing), so I am interpreting that its the top value of all 4 dice, which most likely will be a single die unless there is a tie on both sides. Only in 1e: you can figure out the consequences right here.
5) only in 2e, described in the "First" step: remove the dice that are not the top value, so of there is only a single top value on one of the sides (as most of the times will happen), you would remove any of the other dice so then most of the times the other side will end up with no dice, and therefore a critical (according to the next 2 bulletpoints after the "First" step .
6) both 1e and 2e: If there is a tie, remove the dice not in the tie, and reroll the tied dice. Only in 1e: if the tie is in dice from a single side, thats a critical success for that side.
7) calculate the margin
If the intent is to keep the same mechanic as 1e, I think what happened is that the explanation of the ties from 1e was put in 2e as the "determine the result", so 2e may be missing the explanation for the no-ties normal roll... Check that the "Ties section" in 1e match exactly with "Determine the result" of 2e, therefor leaving 2e with no further for the ties than rerolling.