In python version 3.10 and 3.11 pdb debugger has a bug. If you run python3.11 -m pdb ./your_file_name.py, you will see next

(venv) user@laptop% python3.11 -m pdb ./main.py
> Path/to/file/main.py(1)<module>()
-> a = 10
(Pdb) 

if you type command l (list) you wiil get

(Pdb) l
  1  -> a = 10
  2     b = a + 5
  3     c = a + b
  4     
  5     print(c)
[EOF]
(Pdb) 

But if you type ll (long list), you will see next

(Pdb) ll
  0     a = 10
  1  -> b = a + 5
  2     c = a + b
  3     
  4     print(c)
(Pdb) 

you can see cursor '->' show different positions.
I reproduced it for version 3.10 and 3.11
In python version 3.8 everything is fine. There is no problem. The position is the same.

My environment

Macos Monteray 12.6.5 CPU Intel

python 3.11
python 3.10
python 3.8