Screenshot: (available, but I have to download it from my Switch first)
Description:
The first time a Gargoyle Gem appears on the board, Luther pops up to explain them – but gets the description wrong:
Destroying Gargoyle Gems actually affects all targets (allies or enemies), which is the better behavior.
EDIT: Apparently this was also reported when it originally occurred on PC at that start of this campaign.
Otherwise, this cannot be strictly reproduced because these tooltips only appear once.