Bug: primary selection cleared when deselecting text

[mentha-spicata]

 * xed - Version 3.6.6
 * Linux Mint 22

What is "primary selection"
"Primary selection" is operated in the following manner:

• copy text by selecting it
• paste text by clicking middle mouse button

Issue
Xed clears the primary selection when text is deselected.

As a consequence you can't do anything between copying and pasting, such as moving the cursor to a different spot or let alone edit the text, without losing the content of the primary selection.

Steps to reproduce

1. select a text to copy it into primary selection (can be verified with xsel --output --primary as long as you don't deselect it!)
2. click anywhere else in the editor or move the cursor with keyboard - at this point the primary selection is cleared (can be verified with the same xsel command)
3. press middle click to paste the text: nothing happens

Expected behaviour
In all other software I've every used the text stays in the primary selection once it has been selected, even if later deselected and even if the originating program (of the selected text) has been closed.

Other information
This bug is not a recent regression and may be present since the beginning.