Not really a bug, or is it? idk. But I always notice especially with this update, that when I go to play grim reaper from kecks fan songs I would always have a miss right at the start of the song once the notes show up. Apparently, there is this random note that pops up and that you pretty much have to guess when to hit since your note field is invisible before the song even starts. Just felt like pointing this out in case this was unintentional...
#Invisible note right on the start of grim reaper
keen spear
unkempt carbon
should be fixed next patch