After latest upgrade a portal is made to another folder

After the latest update a folder - not at all related to a folder that I’m working on now - has turned into a portal.
Next image is the folder I’m working on now and after every heading there is a ‘1’ . Clicking on it, it says it’s a portal to another folder:

Scrolling down on one of the topics on the lef i see this:

Strange, because these two are total unrelated folders. I’m sure I did not make a portal from one folder/file to the other one.
It seems I can’t ‘unlink’ both folders

Here is the folder pane:

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