Clicking away from rendered markdown cell unrenders it

[krassowski]

Description

When an active cell is a markdown cell and user clicks on a different cell, the markdown cell unrenders causing content jump thus distraction and annoyance.

Reproduce

Interestingly, this does not happen when:

• changing the active cell with arrow keys
• clicking outside of the notebook or on its toolbar

Expected behavior

Clicking on another cell does not unrender the previous cell.

Context

• Browser and version: Chrome
• JupyterLab version: 4.1.0b0

Likely a regression in 4.1.0beta but Binder does not start for me at the moment so I cannot confirm.

[krassowski]

Confirmed I do not see this in 4.0.9 nor 3.6.x.

[JasonWeill]

Is this an issue in 4.0.10 as well?

[fcollonval]

It may be a consequence of #15408

My guess, the focus change switches the notebook to edit mode before the active cell index is updated.

[afonit]

Is this an issue in 4.0.10 as well?

I do not see this behavior on 4.0.10