Spread footing design according to AASHTO with multi column pier


I am designing a multi column pier on spread footing in LEAP I noticed that the option in A/D parameters of designing footing per AASHTO disappears once multiple columns are specified in the model.  Is this a bug, since and do not say that they are not applicable to multi column piers? I assume the analysis would be conducted such is not considered?

When there is only column specified, option for exists 

When there are multiple columns specified (two in my test case), option for does NOT exist