I suppose it might be a glitch, but usually your team advances when you pass certain spots on the map. If the mission should end when you see the final "objective completed" and your squad advances to the turret.
If you didn't get objective complete, then there is still an enemy somewhere, and your squad is probably lagging behind pinned down by enemy fire. Check the area on the right... maybe there is an enemy still hiding in there.
If your squad is at the turret overlooking the bay, your objectives are complete (check by pause menu) and the mission isn't ending, then I suspect glitch.