Ionic 3 split-pane - menuToggle not working


I am trying to adapt an app from mobile-only view to support also tablets, with split-pane, but the menuToggle button, that should show the overlay menu, is set as hidden. Even if I add css to force it to appear, tapping it does nothing. Without the split-pane, it works as expected. Here’s a short version of the code:


<ion-menu type="overlay" [content]="rootNav" [swipeEnabled]="false">
<ion-nav #rootNav [root]="rootPage" swipeBackEnabled="false"></ion-nav>


  <ion-split-pane [when]="isTabletLandscape()">
    <div class="columns">
      <section class="column favourites" main>
        <div *ngIf="isTabletLandscape()">
          <ng-content *ngTemplateOutlet="navbar"></ng-content>
      <section class="column">
        <ion-nav #detailsPane swipeBackEnabled="false"></ion-nav>

<ng-template #navbar>
  <ion-navbar class="navBar">
    <button class="buttonContainer" ion-button menuToggle>
      <img ion-img src="./assets/images/dashboard/burger.svg">
    <ion-buttons end>
      <!-- other buttons -->

Browser output snippet:

<button class="buttonContainer disable-hover bar-buttons bar-buttons-ios bar-button bar-button-ios bar-button-default bar-button-default-ios bar-button-menutoggle bar-button-menutoggle-ios" ion-button menutoggle **hidden** >
  <span class="button-inner">
    <img ion-img="" src="./assets/images/dashboard/burger.svg">
  <div class="button-effect"></div>