CCM can adjust the Locations bandwidth during the call setup. This just depends on the config and what devices are invoked during the setup. The two seconds could just simply be the delay the monitoring tool has between polling the counters. It would be best to look at Detailed CCM traces of the call to see what is happening with the Locations bandwidth and the call setup.
If you need help with the traces you can email them to me and I will look when I get a chance or you can open a TAC case. Please provide the call time, called number and calling number. Will need traces from all CallManagers involved with the call, ie, Where the GW is pointed to and the CCM the FAX machine is registered to.
Kevin