Chances are you were re-bucketed. You are now being compared to others with similar reports instead of others who have public records on the CR.
As for the PIF instead of trying a PFD on the collection because of age.......I was told collection accounts don't count as age. Meaning if you have an open, good standing CC from 3 years ago and a collection from 4 years ago.......your oldest account is 3 years, the age of the collection is ignored. True or untrue......not sure......just what I was told.