It's annoying, and it's a pain for a week or so while they're working it, but hindsight it's not the end of the world. FWIW I think EVERYONE in my indoc class of 14 had a hang-up of some sort. They were "unable to verify my employment" at the flight school I instructed at, and it turns out they called them at 9pm on a Friday, obviously no one answered, so they marked it down as unable to verify employment. They were also unable to verify my start date at my previous employer after requesting a paystub and W2 (neither of which had a start date on it) until I called them and gave them a number to call, and an exact time-frame window of when to call it, ie. normal business hours. All this was happening while also holding a security clearance with the DoD, which I thought was ridiculous. That said, the hiring team knows their 3rd party background check service can be a pain and is understanding if you have hang-ups over small things that shouldn't even be an issue.