Map boss dropping same-tier waystones instead of 1 tier higher

Bug Report ID: #2250324515

I've suddenly stopped getting higher-tier waystones from map bosses. One day, 100% of the waystones dropped from map bosses were 1 tier higher than the map I completed. The next day, 100% of them were the same tier.

I should add that this happens regardless of waystone tier, and it persists in irradiated maps (or other +1 area level mods), although the waystone dropped does still properly inherit +1 tier from the +1 area level mod.