Any answers you might receive here will be speculation. Likewise, I would not regard any statement by a first line customer service representative to be authoritative.

Have you retrieved fresh copies of your credit reports to see what is reported? By law you are entitled to download your credit reports once every twelve months at no cost from this site...

https://www.annualcreditreport.com/cra/index.jsp

These reports will not include your FICO scores, only the underlying data. I would not purchase the scores until I had reviewed the reports. Did Chase tell you which bureau they used when reducing your limit?