Ok, running the gfix -sweep with everyone logged out did work and only took about 5 minutes. I believe the issue came from me only trying to run the sweep one time and a transaction being stuck. I never tried to run sweep AFTER restarting the services. I also think there was confusion because I was under the incorrect assumption that gbak was doing a sweep while backing up.
I really appreciate everyone's responses that help me get to the root of the problem. Thanks! Ryan