Unlinking main site from subsite

Hi,

On my multisite I once linked two sites (one being “localhost/wp” and the other “localhost/wp/subsite”) via MultilingualPress by ticking the relationship box and now I cannot unlink them. They still appear in the language menu on both sites.
The language menu should consist of 2 flags but now there′s 3 with the linked site having the default/native language flag being displayed. The only way I can unlink them (to remove the flag from the menu) is to archive the subpage.

Things I′ve tried:
– untick the box in Network Admin under MultilingualPress -> Relationship
– clear the browsers cache
– changing the subsite′s URL

Could you help me out on this one?

Thanks in advance!

BR,
Risto