`Paste` from `Edit` menu won't paste from system clipboard

- add some data to the system clipboard
- open `Edit` drop-down menu and select `Paste`
- expected clipboard content to be pasted into the buffer

Typing `ctrl-v` will paste from the system clipboard, however using the command from the drop-down menu won't.

Reproduce the issue by copying data to the system clipboard, selecting Paste from the Edit menu, and comparing it with Ctrl-V. Trace the Edit menu's Paste command alongside the working Ctrl-V path, then verify that the menu action inserts the clipboard content into the buffer and add or update a regression test if the relevant test entry point is found.

Written by the indexing model from the issue text.