Differences in arm slot

When I break down my mechanics my arm slot is higher then when I throw the ball. Same for when I do dry throwing or the towel drill. Is this because of shoulder fatigue or weakness? I feel like my shoulder hasn’t been very strong this whole year and it gets sore pretty easily.

It’s quite possible. Or you may be trying to throw from an arm angle that isn’t comfortable for you. In any event, if you could post a video so we can get a look at it and see what’s going on…I might have some answers for you.