Opening a notebook on remote, closing it, and reopening it does not reuse the same kernel

Switch to remote jupyter.
Make some cells like so:
```
a = 1
```
```
print(a)
```
Run all cells
Close notebook
Reopen.
Run JUST second cell.

It should print A = 1.
It doesn't open the same kernel.

There's a test we had that was supposed to verify this but it was artificially forcing the right kernel to be selected.