LY, as you know if you are getting only 94 amps at 14.4 volts Eg, just crank the voltage up a little and you should see the 100. But that unit might be faulty in some way,
I have had two PowerMax 100 ampers, one with the adjustable pot knob on top. I always got 103 or so amps from either one. I have seen where one of them sort of ramps up starting from say 96 amps and rises to 103ish in about a minute then holds there. I also have a 55 amper that does 56.x and a 75 amper that does 75.x ( I have collected these over several years of changing my set-ups in different RVs) My smaller gen that I can carry in this MH (Honda 3000 too big) will just barely run the 75, so can't use a 100 anymore.
I don't know why that one does only 94. I also had a newer type Parallax 4455TC that did constant 60-81 amps when using fat wire with it and under 55 amps using skinnier wire. Time2roll also said his 55 amp WFCO back when did 60 amps
It is true converters do all seem to output lower amps with lower 120v input.
Perhaps you will discover why that one only does 94 once you tinker with it some more.