How do I deal with deductions from payroll by the employee for health insurance premiums?

I am a new Quickbooks and payroll user.  I am having trouble figuring out how to deal with deductions from our employees' paychecks which are basically reimbursements as we generally pay the bill electronically the first of the month and then during the course of that month, we deduct the employee's contribution and also show a company contribution for each employee for the remainder of their premium.  
My dilemma is that the money that we deducted/contributed for the health premium during the month of January was actually reimbursement for a bill actually paid the bill early due to the holiday, so the payment was actually made in December and was already accounted for in a profit and loss statement in Dec. 2019.   So while I was able to apply these liabilities to the payment made in December so they are no longer showing as being due.  But my problem is that since they were deducted in January pays, they are showing up as expenses on our profit and loss report for the month of January. I do not want them to show up there since they were already counted as an expense in  December.  
I do not believe this will be a problem in future months as we now have all the payments set up to be paid the first of the month so the payment and deductions/contributions will all fall in the same month.  
But, I have no idea what to with this month.  
Another related question is if I should leave these payroll items listed as liabilities or not since they are actually more of an reimbursement to the company.  The main reason I set all of our company contributions and deductions thru payroll is because I need them split among offices/classes as many of our employees work at more than one office, so their amounts are split by various percentages which have already been put into payroll to split the wages.   Please let me know if there is a better way to set these items up.