It's a Ren'py issue, unfortunately - the stat is increasing, but the visuals don't change until you change scenes. Nothing I can do about it at this point in time :/
Viewing post in Weekly Update: v0.11.7 - LUNA PREGNANCY! comments
All good.
I knew the skill was increasing, well at least confident based on my own renpy code knowledge, "stat +=1" so assumed it was a visuals thing and thats it.
Still thought to pass it on incase you hadn't known :)
Anyway, found your game yesterday and have thus far quite enjoyed it.
Looking forward to further content, and a little awed at your weekly update commitment.