Your formula is correct, but I think the problem occurs in your reference to the field names. I notice that all your field names have spaces in them. Spaces = bad when it comes to SharePoint. Most likely what happened is that SharePoint assigned the field name behind the scenes to be "In%20AD" instead of "In AD" etc.
Try substituting the spaces in your field name references of the formula with %20 instead i.e.
=(IF([In%20AD]="Yes",1,0) +IF([In%20Auvik]="Yes",1,0) +IF([In%20LANSweeper]="Yes",1,0) +IF([In%20Sophos]="Yes",1,0) +IF([In%20VSA]="Yes",1,0))/5
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