Increasing number of minions (only in indicator)

The number of indicated minions on the icons increases when quick-swapping weapon loadouts. Both weapons have spirit modifiers, but not equal values.

The screenshot shows 160+ minions.

https://imgur.com/c3rrJgT

Stumbled upon the same bug, seemed to happen for me only after changing my weapon from one sceptre (30% in spirit ) to another sceptre (16% inc spirit).
As in some other bug report about this (and also as in your screenshot), i encountered the bug using arsonists.