Remove voices in drumset or make it more perspicuous (especially for beaming)
The separate voices in the drumset are confusing - sometimes the instruments are placed in one voice and sometimes in another. It is difficult or impossible to get the beaming between voices done correctly. I haven't understood why there should be different voicings in a drumset at all. When I want a separate voice for a drum instrument, say the bass drum, I select that instrument alone on a separate stave.
Comments
The different voices are supposed to correspond with left and right hand and foot
There are actually a number of different standards for how the different voices are used in drumset music. In the United States and I assume at least some other countieis, the most common is for voice 1 (stems up) to be used for any notes to be played with the hands, voice 2 (stems down) to be used for any notes to be played with the feet. This is the way most drumset music is published in the US, and this is how the default drumset in MuseScore is defined. However, I gather than in France and perhaps some other countries, it is more common to do this differently - stems up left hand or foot, stems down for right (or maybe vice versa). And because the notion of duration has little meaning in drumet music (except for rolls, I guess), some publishers have chosen to do away with voices for the most part and notate everything in one voice with stems in the same direction.
MuseScore provides an already-configured French drumset, but if you want to create or customize your own (such as to get everything in one voice), you can do that too. Right click a drums staff and select Edit Drumset to bring up a dialog that allows you to customize the notation of each drum - which line or space, what notehead, stem direction, and voice.