エラーは確認できませんでしたが、特にボタンの配置を変える訳でも
ないのであれば、ボタンの表示だけ変える方が良いかも
screen 0,1000,700
cls 1
font "",20,1
objmode 2,1
objsize 150,40
pos 0,0 : button "A",*a
pos 150,0 : button "B",*a
font "",20,1
objsize 240,60
sdim sayaka,,2,6
sayaka(0,0) = "A−1"
sayaka(0,1) = "A−2"
sayaka(0,2) = "A−3"
sayaka(0,3) = ""
sayaka(0,4) = ""
sayaka(0,5) = ""
sayaka(1,0) = "B−1"
sayaka(1,1) = "B−2"
sayaka(1,2) = "B−3"
sayaka(1,3) = ""
sayaka(1,4) = ""
sayaka(1,5) = ""
m = 0
y = 50
repeat 6
pos 760, y : button ""+sayaka(m,cnt)+"", *沙
y + 60
loop
stop
*沙
n = stat - 2
notesel form : noteload ""+sayaka(m,n)+"" : objprm 0,form
stop
*a
m = stat
repeat 6
objprm cnt + 2, sayaka(m,cnt)
loop