Cannot Hit Mobs When Big

[Demidiu]

Hey, So Basically I am making an Origin using the origins mod, And It is a giant. It has its scale set to 6.5. And For Some reason when I am in survival I am unable to hit any mobs or entity's (other than the giant mob) But When I am in creative I can hit anything, Any Idea on how to fix this? I have tried changing its reach, and everything and nothing works, unless I make it normal sized then I can hit mobs