That does seem strange.
There is a possibility that the unit you are in has a cross unit factor that will add an amount from the cross unit to your total, but EQT usually lists these separately on your check showing more than one interest. Another possibility is that there is a “working interest” owner in the unit that is affecting your payout with the possiblity of a “bonus” or “enhanced” decimal interest for you. I’ve had that happen once with another company. The other possibility is that there was a calculation error - but not likely with the computer doing the math.