ToME: the Tales of Maj'Eyal

I an encountering a bug where I am unable to refund 4 of my class points. More specifically, I am spending points in Call of the Crypt, summoning the skeletons, and then trying to refund the points. Most of the time it works, but many times now, it has not. Just want to point it out.

The game doesn't allow refunding of points during combat or several turns after combat ends. Could that explain your experience?

To elaborate, sometimes, 1 point becomes unrefundable. I know when I can and can't refund. So I put in 4, but sometimes I can only pull out 3. Nothing else has had points put into it.