Connecting Rods Hitting Oil Pan Baffle?

[RHD]

I think the pan came loose when you first drove the car. The noise would have disappeared when the big end scoop wore through the pan.
Some pans need a good knock to get into place in the sump. Look for metal fragments in the oil. Best to drain the oil, remove the sump for a complete clean out and reinstall, making sure the pan fits snugly.