Validation Issues SPOnline

Greetings. 

I have a list with two columns needing validation. 

[StartDate] [StopDate]  Both are Date&Time fields.

I have validated the [StartDate] column validation to =StartTime<=NOW() -to prevent dates greater than Right now being entered.

I have validated the List to =TE_StopTime>TE_StartTime -to prevent the StopDate being less than the StartDate.

On the NewItem form-everything works just like planned no problems. 

The problem arises on the EditItem form-  I keep being told an existing item that has already passed validation no longer passes.  I'm being told that StopTime is GREATER than StartTime even though it's not!!