404 after cleaning audiences

We removed all audiences and created a new one. Now we are getting 404 errors. It seems the list ID does not exist.

I synched the lists in mc4wp and they are correctly displayed. The form uses the correct list too. Anything else we can try?

All returning 404 errors:

GET:

https://us20.api.mailchimp.com/3.0/lists/976e35dcaf/merge-fields
?count=100
&fields=merge_fields.name,merge_fields.tag,merge_fields.type,merge_fields.required,merge_fields.default_value,merge_fields.options,merge_fields.public

https://us20.api.mailchimp.com/3.0/lists/976e35dcaf/interest-categories
?count=100
&fields=categories.id,categories.title,categories.type

https://us20.api.mailchimp.com/3.0/lists/976e35dcaf/members/bc10bd82a4d6ad3065f523142a761507

POST:

https://us20.api.mailchimp.com/3.0/lists/976e35dcaf/mem

Thanks,
Christoph