@SILVERisSORRY This also happens to me more often in this season, especially in encounters Seer and Bloodhound. I can't really tell if the sound is too low or not triggered at all, but I noticed other voice lines missing completely as well, especially those from the teammates confirming that they've downed an enemy. I usually don't have issues with the direction of the sound, but I've had a few situations where the sound of a legend seemed to be lagging, indicating a position that was way behind the enemy.
All these, coupled with the fact that some experience game freezes, crashes or even device shutdowns, suggest that there are memory management / performance issues. I can't recall having any audio issue in Arenas, for example, where's way less clutter, but in BR they do happen , regardless of the current map.