Payroll admins see deductions silently stop after open enrollment changes

Recently set up new deductions for open enrollment in September. I ended the old deductions and entered an “end date.” Entered the new deductions with effective dates and “begin check” dates for the first week of September - no “end dates” for the new deductions were added Deductions have been coming out of paychecks like normal, and all of a sudden this recent pay period the deductions did not come out. I check the affected employees and the “begin check” dates have now all updated to 10/15. Anyone know what may have caused this or experienced this issue themselves?