Can't get rid of annoying staff...

As the title says, these annoying staves cannot be selected, removed nor hidden… I’ve googled it to death and looked in every single menu, but can’t get rid of them…

Any ideas? Is it a known bug?
Bug 2.PNG
Bug 1.PNG

You’ll need to post the project to see what’s happening

I’m sure if you show signposts in your score you’ll see the signposts that correspond to the ossias you’ve created, and then you should be able to select and delete them.

Of course, the signposts…! Thank you lovely Daniel as always.