It is possible all you references were good, but some were "form" or not expressive enough.

One of my old employers had a very strict policy of only issuing a standard reference which was basically to confirm I worked there, my job title and my start/finish dates. Staff and managers were expressly forbidden from giving references - they had to refer all requests to HR.

I had a job offer withdrawn as a result of this. The potential employer asked specific questions in their reference request and my old employer refused to answer then - instead giving them their standard form reference. Not my fault, and nothing I could do about it.