Hi jokello68,
I have checked your site and see that the issue is fixed on the mobile, not the desktop. But a workaround is possible using aria-label and aria-describedby. Please insert your helper text in a hidden label and give the id of that label to aria-label.
You can open the \templates\uber\tpls\blocks\off-canvas.php file . Find line 20 then use the code as the following code:
<button class="btn btn-primary off-canvas-toggle <?php $this->_c('off-canvas') ?>" type="button" data-pos="right" data-nav="#t3-off-canvas" data-effect="<?php echo $this->getParam('addon_offcanvas_effect', 'off-canvas-effect-4') ?>" aria-label="open_menu" aria-describedby="click-to-open-off-canvas-menu">
<label id="open_menu" class="hiddenlabel" style="display: none;">Click to open off canvas menu</label>
Hope this helps!