Altitude inconsistent

Hey People,
I have a Pixhawk 6C mini with a BZ-251 GPS. The altitude at ground consistently showed 9 or 10m and above on the HUD. Even while flying at approximatly 5m, it showed up as 15m instead. Could anyone help me with this issue?

I am confused as to what altitude I was seeing on the HUD since the baro alt seems below 6m at all times.

Here is the screenshot of graph with baro alt, gps alt, xkf1[0].PD .
Here is the log file - https://drive.google.com/file/d/1UUH7kKnOIxFRX_XVOlCyY3XftYti7Jtb/view?usp=sharing

It was a EK3_SRC param issue.