multi-GPU map does not work
### Describe the bug

Here is the code for single-GPU processing: https://pastebin.com/bfmEeK2y
Here is the code for multi-GPU processing: https://pastebin.com/gQ7i5AQy

Here is the video showing that the multi-GPU mapping does not work as expected (there are so many things wrong here, it's better to watch the 3-minute video than explain here):

https://youtu.be/RNbdPkSppc4

### Steps to reproduce the bug

-

### Expected behavior

-

### Environment info

x2 RTX A4000