The rest of the circuit design seems to be correct. My only suspicion goes towards SW1 and SW2 pins of LTM4615 are both connected to 5VDC Vin. I think I made a mistake.
The datasheet only has this to say regarding this pins:
" The switching node of the circuit is used for testing purposes. This can be connected to copper on the board for improved thermal performance. SW1 and SW2 must be floating on separate copper planes".
Can you please guide me whether we should power up our board regardless of the SW1 and SW2 pins connected with 5V?