Hello,
I made a PCB using an LTM4646 chip to generate 1.5V and 3.3V from a 12V supply.
All three of the power nets, 12V, 3.3V and 1.5V are shorted to the GND net in the finished board.The PCB manufacturer checked them out with an X-Ray to verify the issue was not with the manufacturing of the board, so I wanted to see if my design looked correct to this community.
Here is my setup in LTSPice, which is the design I used on my PCB. It simulated the correct voltages just fine.