Weird sidebar issue

Just an update for anyone who is interested, @cteduard has been extremely helpful, and between us we have managed to eliminate various things and isolate the issue, although it is still not completely solved in terms of yet knowing exactly why it is happening. However I have been able to come up with a workaround, that I am going to summarise here for anyone that needs it.

Basically the reason this was happening on my site was that when Buddypress menu links connected to the user profile are added to the Blocksy/Wordpress menu (under Appearance > Menus via Add menu items > Buddypress Member) something occurs so that these links do not work correctly – this is what is still a mystery. My workaround, now this is known, was to create my own custom links in the menu, which are then redirected to the correct Buddypress link via a redirection function in my child theme’s functions file. This is necessary because each member’s profile links have their user login within the link. If anyone needs the code for this please let me know, but hopefully the clever Blocksy guys will be able to work out exactly why the Buddypress menu links don’t work properly and report back here.