When you sort by lvl cantrips and lvl 1 spells are mixed together.
I noticed this as well. One thing you can do is if you open up the filter, you can set the Cantrip field to true (to display only cantrips) or false (to display only spells). All the same though it would be kind of neat to maybe add the cantrip designation as a sortable field(?) so that you could quickly and easily delineate between the two while still having them all appear in the same list.