Normal
Input is stop driving it like that dude, if you’re serious about driving strictly in manual mode for “only” 20k miles….thats a helluva a lot of wear/tear on the TC & clutch packs…could be something simple like solenoid but if you’re under warranty why even F around at all? Bring it in asap get the issue documented & in fords system so even if it’s not a big mechanical issue now, in the event there is & you’re closer to warranty expiration you already have something on record