After more investigation, it appears that on mobile devices the submenu items are visible from pages that are one step down (and lower) in the menu structure, but not from top tier menu pages.

Hello

May I suggest sending temporary administration access to your Joomla installation to info@joomla51.com and we will examine this issue further. For our reference please paste a link to this post in your email.

Ciarán

Thank you Steven

Could I ask you to try installing 'jQuery Easy' which would help in resolving any Javascript conflicts. A guide on installing 'jQuery Easy' can be found here... https://joomla51.com/tutorials/item/resolving-javasript-errors-in-joomla-using-jquery-easy

Failing that may I suggest allowing us access to your Extensions Manager and we will examine this issue further.

Ciarán

Thank you for your prompt reply! I have granted your Super User status so you can the access you requested.

I have also installed 'jQuery Easy as you suggested. Console reports mootools error <Use of getAttributeNode() is deprecated. Use getAttribute() instead.> and jquery <Use of getPreventDefault() is deprecated. Use defaultPrevented instead.> issues, neither of which I understand.

Steven

Ciarán -

I assume you did something, because the menu is working on my mobile device! Thank you very much! Please let me know what you did, so I will know what the problem is if it ever arises again. Thanks a lot!

Steven

Thank you Steven

Nothing done on our end so I suspect you installing 'jQuery Easy' resolved the issue. You may have originally been loading a cached version of the site which would explain the delayed result.

Ciarán