Boss HP bars have disappeared

For weak bosses (105 and below), HP bars don't appear for me anymore. One day it was there part way through a Manon fight, but it cut off and doesn't appear for me anymore. This occurred before the last patch and happens regardless of whether or not there is a notice is the top. Also, my "meso/item drop" sound never plays anymore, and I wondered if it might be related. Does anyone else have this problem? It's not a big deal, but it is somewhat annoying.

For bosses like Zakum, Pianus, and Pap, it shows up fine.