functionality tested: 'undo' command line typed: 'undo' previous command: 'append 123 f/2700' Expecting the app can undo the mostly recently used 'append' command, however, it is not achieved. The command result shows 'nothing left to undo'  <!--session: 1604044864306-99c301af-2488-4ea3-8d13-ccce34985a78-->
functionality tested: 'undo'
command line typed: 'undo'
previous command: 'append 123 f/2700'
Expecting the app can undo the mostly recently used 'append' command, however, it is not achieved.
The command result shows 'nothing left to undo'