Cursor in jupyter notebook is a green rectangle

I think I may have inadvertently hit some keyboard shortcut on my laptop. Each time I click inside a cell, the cursor is a green rectangle, and it seems to behave in a command mode. If I enter a or i it goes back to normal (edit mode). Which is what I want pretty much all the time, so my experience is very annoying now, each time I click inside a cell, I have to press one of those keys before being able to do anything. Restarting the jupyter server didn't help.
Anyone has an idea how I can restore defaults, i.e. go back to defaulting to edit mode?
(sorry, no screenshot because this is at my job and I am not allowed to share a screenshot. I am attaching a cursor that looks similar. Basically, instead of a simple vertical line, it's a solid green rectangle)

I think you have jupyterlab-vim installed in you environment ( it is installed as a normal package with pip install --upgrade jupyterlab-vim.

in the documentation it says to use Shift+ Escape to Leave Vim Mode

or try to delete the package with pip uninstall jupyterlab-vim