In Leverage Redemption when Parker pretends to be FBI she doesn't use the agent Hagen alias anymore. Now this could have a simple explanation like the alias being blown and no longer useful. However there is an infinitely funnier option.

Agent Hagen is a legitimate FBI agent now, and therefore cannot be part of any illegal business.

I mean, look, it's been eight years and over the course of the original show agent Hagen was pretty good at her job! At some point McSweeten either found out agent Hagen wasn't really an agent and made some corrections or someone working administration found out agent Hagen wasn't getting a paycheck and fixed that problem.

I'm particularly fond of the idea that McSweeten knows that Parker, legendary thief, is agent Hagen but also figures she's helped out so much that he might as well give her a job. Maybe some sort of special investigator position where no one will question that agent Hagen never shows up at the office. Sometimes he finds out about fake FBI agents from the other leverage crews and just... adds them to Hagen's team.

(And of course, all of this applies to Hardison's FBI alias too.)