Hi David

Thanks for posting in the community! Having objects snap to the grid can be a bit tricky! If objects are sized with snap-to-grid disabled for instance and the size does not conform to the grid then only the top left corner of the object will snap to the grid when this feature is enabled. Similarly if groups of objects are positioned so they do not line up with grid-lines then snap-to-grid is enabled and the objects are all selected together only the top and left edges of the group of objects will snap to the grid when the group is moved. I'm not sure if these characteristics are relevant to the issues you are experiencing but please feel free to reach back out if you have specific questions on this functionality. 

this definitely helps thank you!
so if I have this right no matter how things are arranged the top left corner should always snap to grid?

Hi David

Yes in general that is the case. However there are some exceptions. For instance you should always be able to center objects/groups of objects on the page or align them with other objects on the page even if that does not adhere to the grid.