Transferring Mutual funds from 1 broker to another

Mutual fund units gets transferred via CDSL easiest for cdsl-cdsl transfer & via DIS form via cdsl-nsdl and appears in DEMAT.

Can someone explain in detail how to get these transferred mutual funds appear in the dashboard so that we can trade them.

For the MFs transferred from zerodha to kotak, kotak is requesting the ARN code be updated to the AMC. Only then it can be mapped to the dashboard.

When i contacted the AMC directly - they have no clue that i have those mutual funds as its held in demat form.

Why is there a disparity?