Companion spirit reservation bug

I'm playing tactician on PS5 with one companion.
I have 144 spirit on weapon slot 1 and 2 (no passive points that affect spirit).
On both weapon slot 1 and 2 when I activate my companion it says that it reserves 44 spirit.
On weapon slot 1 this is correct.
But on weapon slot 2, with all other buffs turned off, it actually reserves 46.
I assume this must be some kind of bug as the number says that it reserves 44, but I only have 98 left after activating it.
See pictures below.