What we stutterers do is that we try to control our speech through gross motor skill try to force our words whenever we stutter but its a fine motor skill thats why our face goes weird or we face severe blocks and overtime our brain thinks that for some specific alphabets we need to use gross motor skill thats why we face frequent blocks on them. One of the best thing i found about it that don’t force words you cant do it Its not possible whenever you face blocks just stop DON’t FORCE WORDS and restart you would still stutter cause its somewhat a neurological condition but the intensity will decrease and the amount of pressure you feel will also decrease.