Hi Ciaran and thank you
This really is strange. Linking top level menu items to articels = everything is working fine in mobile menu. Using menu type of "alias" causes problems on mobile devices. This does not make sense.
If you like you can check out my demo Carmen. There I have added "Page 2" with submenu "Page 2.1" and "Page 2.2". Page 2 is not of type alias, but is linking to an article instead.
Basically using our template makes the menu behave different as it does if using Protostar template. Using Protostar template there is no chance to access submenu 1.1 or 2.1 on mobile devices. Using your templates at least allows accessing submenu if top level is of type article. It just does not work if top level is of type alias.
Anyway, you said you did a change to the menu so it shows the sub-level indicator icon. What did you change? Will you add this to your templates as well? I'm afraid of loosing your changes if update templates.
Thanks.
Patrick