Notebooks: breakpoints unexpectedly moved when splitting cells

[ronglums]

Version: 1.63.0-insider (user setup)
Commit: ed3018f
Date: 2021-11-23T05:33:39.595Z
Electron: 13.5.2
Chromium: 91.0.4472.164
Node.js: 14.16.0
V8: 9.1.269.39-electron.0
OS: Windows_NT x64 10.0.22000

1. open an ipynb file

2. set a breakpoint in the middle of a notebooks cell, e.g.
   

3. move cursor to a different location in the cell (e.g. line 3 in this example) and split cell from there.

Expected:
The breakpoint remains in the same location

Actual:
The breakpoint was moved to a different line (should have stayed on line 6 in the second cell but it's on line 4 in the first cell)

After an undo, the breakpoint moved to line 16, which again isn't its original location