Some orders cannot be deleted ("delete is light-red and not clickable")

I’m setting up a webshop and have done some testing (not via testorder but from the front). Most order I can delete but there are currently 9 orders which can’t be deleted?!? Some have the word ‚delete‘ in light-red which is not clickable and some orders have ‚delete‘ in normal red but when I click on it, nothings happens.

Anyone got an idea?

I have the same situation and maybe it depends on the linked documents. My orders which I can´t delete have documents and others not.