Reproduction steps: 

Try to expand a group in this dojo:

• https://dojo.telerik.com/aroxoYeB/5 

Workaround: 

Appending the following script right after loading the kendo scripts:

• https://dojo.telerik.com/aroxoYeB/6 

• kendo.ui.Grid.original_groupable = kendo.ui.Grid.prototype._groupable;
  kendo.ui.Grid.prototype._groupable = function() {
      let that = this;
      kendo.ui.Grid.original_groupable.call(that);
      if (!kendo.support.isRtl(that.element)) {
          return;
      }
  
      if (that._isLocked()) {
          that.lockedTable.on("click.kendoGrid", ".k-grouping-row " + "a[class*='-i-caret-alt-right']", that._groupableClickHandler);
      } else {
          that.table.on("click.kendoGrid", ".k-grouping-row " + "a[class*='-i-caret-alt-right']", that._groupableClickHandler);
      }
  }