Time expiration

So I have been in a quest to get my clearance since April 2018. To this date  29 September 2021. I have only had follow up interviews. The last one being Febuary 2021. The last set of questions were about my wife who is from Peru. 
During last interview they talked to a supervisor about my wife said I neve
My question is there a point to where they cant find anything verifying my  old  supervisors account.  They stop the investigation or do they run it to ground?