There are some reasons why KYC can fail,
- bad quality images/photos
- the size is too big or too small (some platforms are allowed to use PDF to solve this size issue)
- the documents are out of date
- the information such as names, date of birth in the platform and the document do not match
- suspected of using other people's documents or fake documents
- etc
If you feel that the documents you have provided are valid, then you don't need to panic and be patient in waiting for an answer from the support.
Because support usually doesn't have the authority to check KYC, so they won't be able to answer your questions until they get an update from someone who checks your documents.