@Fran-Diox That was it! Thank you!

I was using two separate stacks, when I changed the splitter to use the same stack as the navigator it works.

 <v-ons-splitter-side swipeable width="220px" collapse="" side="right" :open.sync="openSide">
      <v-ons-page>
        <v-ons-list>
          <v-ons-list-item
            v-for="menuPage in menuPages"
            :key="menuPage.label"
            tappable
            modifier="chevron"
            @click="setOptions({animation: 'fade'}); pageStack.push(menuPage.page); openSide = false"
            >
            {{ menuPage.label }}
          </v-ons-list-item>
        </v-ons-list>
      </v-ons-page>
    </v-ons-splitter-side>

Is it possible to combine splitter and navigator with a back button? I based my code on the “Combining Splitter and Navigator” example and added a v-ons-back-button but it only works with the “Navigator” pages and not the pages clicked in the side menu.