[Gameplay] "Environment Quality" setting unresponsive, stuck in "Very High"

Since 7.10 (reported it during last patch, sadly 7.11 didn't bring a fix), Twisted Treeline and Howling Abyss environments are stuck in Very High quality setting and applying a lower setting does not change the textures. It causes me to have an average of 25-30 FPS only (with lowest peak of 20) instead of 45-55 I used to have.

Bug doesn't affect Summoner's Rift, only Twisted Treeline and Howling Abyss.

Included video shows, that quality settings doesn't change the textures.