No the Guru Child theme won’t have any code inside that would affect user roles. I would check your plugins to see if there’s anything active that could possibly be conflicting with it.
Other than that, I have no idea what it could be since I’ve never had that issue happen. I’ve also never heard of anyone else with that issue either, so it must be something external (if I had to guess).
You could also try and make sure that everything is updated properly. WordPress, Genesis Framework, etc.