Bug ID: 1'500'988'538: incorrect aftershock % chance display

I have the Earthbreaker ascendancy (20% chance for Aftershock of non triggered skills), Split the Earth notable (10% Aftershock for slams with maces) and the Aftershock support (20% chance for Aftershock) and I'm using a Temple Maul (2h mace). However, the Rolling Slam skill only displays 40% chance for Aftershock. The skill is properly set to only use the first weapon set (the mace).

However it seems to only be a tooltip display issue since I averaged 0.534 triggers of Aftershocks over 86 calls of Rolling Slam.