P6 issue with total float global vs project calendars

Hi all,

Discovered a weird issue with total float and want to see if anyone understands what's at play here:

My default setting for importing a new project was set to “Keep Existing” for calendars.  My project mainly used a Global Calendar on a 6 workday schedule.  I checked the Global Calendar and it was also a 6 workday schedule (no different than the assigned calendar for my activities).  After importing the project, the total float values reflected the calendar day difference between the Late Finish and Early Finish, rather than the correct difference in workdays.  Ironically, the activity start and finish dates correctly assigned the duration in workdays even though the total float was calculated in calendar days.