I assume you use the tweaked preset that is uploaded when you upload the Maximus. If not, skip the fourth line.
You could check the low-band on the plugin and perhaps switch the processing off (try selecting "comp off" in it) and see if it changes something.
Though you also have processing going on on the masterband, so there could still be flaws in the soundquality theoretically.
Why not try sending a copies of the track to 2 additional mixertrack, one highpassed and on lowpassed, and match the cutoffs so you don't get any strange soundquality.
Then apply the maximus to the highpassed channel, hopefully without damaging the kick and getting the clear sound you like. Don't forget to match the phases!
That being said, I'd still recommend you to set the Maximus to default and tweak it by yourself to match the needs of the track better.
Anyway, I too have noticed some kind of flaw in Maximus that's audible in the kicks when adding it to the master even though there's no processing going in inside it (actually tried bypassing on and off it when it was passive).
It sounds punchier, almost like that "oldschool" laser-ish techno-punch that you had in some kicks, which is kind of annoying if you don't want it.