Moving a maximized window to another workspace

[qsmodo]

• Open a two windows in each of the workspaces 1 and 2.
• Maximize a window in workspace 1.
• Move it to workspace 2.
• Switch to workspace 2.

In about 50% of the cases, the moved window vanishes. It can still be focused though and thereafter raised by un-maximizing it.

After I kept repeating the steps (maximize, un-maximize, move to other workspace, ...) in a random fashion — unfortunately the exact steps are unknown —, I managed it to crash Frankenwm with the error

urxvt: X connection to ':1' broken, unable to recover, exiting.