Shortcut "Insert new subtitle at key-down, set end time at key-up" does not work when video controls is un-docked.

[abc16361]

The shortcut "Insert new subtitle at key-down, set end time at key-up" works well when video control is docked. The way I do is:
1, Set "z" as the shortcut;
2, click to locate a start time on the waveform first, then press "z" key-down, and a new empty line is created;
3, click a second point on the waveform to set end time, then release the "z" key.

However, if video controls is un-docked, the shortcut does not work. Hit the shortcut "z" key-down, it creates an empty line, but releasing the key up does not set an end time.

PS., Testing on Win 11, SE4.0.10