Check your app store for the Fidelity NetBenefits app. I've had other Fidelity accounts for years, and when the blackout period ended for the Vanguard changeover, my FDX stuff was already linked to my existing Fidelity accounts. Through the NetBenefits app, I've already made changes to my payroll %s.
And I can see where none of my Vanguard plans have changes %s. Kinda weird that Fidelity is managing another firm's funds/ETFs, but hey, guess this is what we have now.
So far so good. I think it's going to take a few months / paycheck cycles to really see if I can track the progress like we were able to do in Vanguard.
Hope this helps.