Often I encounter this bug where after killing minions in dominion they fall to the ground but still block your way.
Here is an example.
This started happening probably sometime after Assassin's Creed event. I think since Year 3 Season 1.
So I tried a custom match of breach and couldn't replicate the bug there. As soon as the pikemen die I can pass through them fine, even before they fall to the ground.
Even in dominion not every dead minion blocks my way, only some seem to block it. But for someone who spends a lot of time killing minions, I encounter it pretty often.