End of cut -> height to low / not repeatable?

Hi Lads,
I’ll try to make my issue as clear as possible:

I have 40 small wouden boards that need the same shape cut into,
I’ve made a jig to lock it and all the boards are equally dimentioned.

I have a Z probe and set my material height that way for the first cut →
What I have noticed → if i cut fe 15mm deep it homes back at the end but only raises the Z 10mm so ends up cutting a 5mm groove… (I’ve already set both safety heights to 40mm to no avail)

Also: if I take fe a 5mm board it does the cut perfectly, lifts out high enough,
moves to home, but if I start a new cut, with again a 5 mm board and select 'use previous xyz points,
the bit goes to starting position and plummits ±10mm to much…

So I would guess all this comes back to a software Z-issue…

Is this by design? / can it be helped?
or is there any way to make repeatable cuts on identical stock without reprobing all the time.

Thx in advance!