https://bit.ly/3sg3V0b
簡單說,下周保底要開15層KEY這周要限時18或者19以上燒掉
Hello Krystallíne!
When Season 3 begins next week, Mythic+ Keystones will be lowered by an
additional 3 levels to account for the overall increase in dungeon
difficulty. If you’d like to open your Great Vault next week and earn a +15
Keystone, you’ll need to time a +18 or complete a +19 untimed before next
weekly regional maintenance.
Hope this helps clear things up.