What you were expecting to happen, and what actually happened:
Splintered golem is at mythic ascension, should deal 5 x 150 = 750 damage to boss. Actual damage number showing up is only 450. This isn’t just a visual error, boss has combined total health/armor of 247 + 244 = 491, stays alive with 41 health left.
How often does this happen? When did it begin happening?
Ever since this Raid Boss event, screenshots from the previous Raid Boss event show the total damage working correctly. It’s currently unclear whether Splintered Golen is at fault (e.g. due to boosting off the ascension level of some other troop) or whether the 7.2 update broke something.
Steps to make it happen again
Cast spell of Splintered Golem at boss, check damage numbers. Combined health/armor of boss must be high enough to survive the spell for full damage number to show up.
EDIT:
Root cause might be the configuration of Splintered Golem:
It would be nice to get this fixed fast, while the Raid Boss event is still running. The bug reduces damage output against the boss to 60%, significantly increasing the difficulty level of racing the kill timer.
This bug doesn’t affect the scoring. However, when the Godslayer doesn’t do the damage it should do can affect the outcome of the battle, resulting in losses which then affect the overall user score when they have to fight the same level boss again.
Nevertheless, I also hope this clear bug gets solved quickly.
What you were expecting to happen, and what actually happened:
Splintered Golem should have 5x multiplier (137 x 5 = 685 damage) when fully ascended, but it only has 3x multiplier (137 * 3 = 411 damage).