https://drive.google.com/file/d/1vKiHhnhVPRcAF_f98zCb3PUqa3fCgAM9/view?usp=drive...
here's a renpy project stripped of everything to make sure there's nothing else that might be the cause.
transform enter(p=0.0):
alpha 0.0
pause p
easein 1 alpha 1.0
transform leave:
on hide:
alpha 1.0
easein 1 alpha 0.0
screen choice(items):
style_prefix "choice"
vbox at leave:
for n, i in enumerate(items):
textbutton i.caption action i.action at enter(n*0.75)
and code case you need it