If a document still has a document status of Awaiting signatures, but the recipient says they have signed it, there are some checks you should make.
Ask to check that the document has been signed
Check with recipient that they have indeed signed the document. This is just in case they are mistaken, signed a different document, or it didn't work.
Check they submitted after signing the document
When they sign a document, a common mistake made is to forget to click Submit and Close at the top of the document after signing it. The document isn't classed as signed until this has been done.
Ask the employee to check they have submitted the signed document, and also clicked Close.