Following last week's extended maintenance, players on Classic Era, Hardcore, & Season of Discovery servers were given some new UI features, including updates to Raid Frames, Namplates, and the introduction of Edit Mode. While this new patch initially caused some disruption in addon functionality, the issues have mostly been ironed out. However, one new bug from patch 1.15.9 appears to be a group of over 20 random enemies underground at the entrance of Boulderslide Ravine in Stonetalon Mountains.
While this bug seems to be mostly harmless, there have been instances of Hardcore characters dying or nearly dying to these underground mobs. These enemies range in level from 12-54, so any low-level hardcore character who is making their way to the quests Boulderslide Ravine or Earthen Arise should steer clear until Blizzard resolves this issue.