Sextuplets acting weird?

I've been trying to make a completed version of "The Senate" for my drumline. There is this one part in the cadence where the tenors go into sextuplets, but when I put them in, Musescore just jumps past them without making any sound.
There is a senate w/ working sextuplets, but I need the practice, and it isn't entirely the version I'm looking for.
Just noticed this, the question with the potential easiest answer is how to put in sextuplets without effecting the other instrument's rhythms.

Found solution: make sure you have a quarter note selected when you add the sextuplet