can't delete type

I have some old types I don't need anymore and I want to delete them. But when I try to do so I get an error message telling me, that there are still articles associated to this type.
When I look at the type overview it indeed shows me that there are 7 items associated to the type. But when I click on the "[view items]" link it doesn't show me any article at all.
I tried filtering and switching off filters, all article states, every state alone and so on but these articles seem to not exist anymore but just as an association in my database. How can this problem be solved?
Best Regards

Hello

you do not mention trashed items

did you check for trashed items ?

yepp, also checked for trashed items

Hello

did you check for "all" or for orphans or for items in unpublished categories or in trashed categories ?

OK, getting closer: 6 of 7 articles now showed up as "published" and are now deleted (even though I'm sure I checked "published" multiple times before and they were not there...).
One to go:
Checked all states: normal, published, unpublished, trashed, achived, orphan and all in all possible states of the categories. All other filters are set to neutral except the type dropdown, which is set to the type I want to delete

strange: I now checked the database. The Type ID is 6 so I checked table xxxx_flexicontent_items_ext for articles with this type-ID and I found one with itemid 4381.
When I now in my backend look for articles with that ID I get the same problem: No article with this ID can be found, not even when I browse my articles.
So I went to the database again and looked in table xxxx_content for ID 4381 and guess what: there is no such ID. I have 4379 and the next one is 4382.