Mobile menu glitch

I have tried searching for the answer to this on this forum but couldnt find one. Apologies in advance if i missed it somewhere. I will blame it on my advanced age.

The problem is when i am trying to add a drop down with multiple products in the menu (ie, in this case – the menu item “Dinnerware”), it is visible on the desktop but on the mobile , the drop down for this particular menu item does not appear. Others do work all right though. I have tried removing, adding items etc. No avail.

I also thought it could be a plugin conflict with WP Rocket, so disabled it. No avail. I am at my wits end. And not being tech savvy, I am at a slight loss. This was a project I started after retirement and things were going reasonably well until now. Any help would be highly appreciated.

The page I need help with: [log in to see the link]