possible bug in 4.14.3

i am working on a project using ue4.14.3, were my projectile will not collide with anything. im getting the impression that the actor in 4.14.3 has a bug in it that stops collisions.
boiled down to this simple test

create a project in ue 4.14.3 and one in 4.13 using the blueprint format

place a simple actor on a floor in both

and play

the 4.14.3 will fall through the floor and i have found nothing that will stop it

the 4.13 will act the way its suposed too

and not fall through the floor

is this a bug? or am i just missing something
any help would be greatly appreciated.