This bug was reported by several users/contributors of the CMS of the city of Lausanne.
It is very annoying not being able to copy the useful title or message body of an error or a warning message on the pulse especially when this content contains the path to the source of the bug or the page to check.
We saw that on the CSS of Magnolia we have on the body: user-select: none;
We tried several browsers before posting the ticket.
Thank you in advance for your support,