Has anyone noticed this behaviour and is there perhaps a workaround?
It is clearly reproducible with deleted cookies or in incognito mode of the browser.
So you enter your TikiWiki page for the first time and everything loads normally, then you reload the page or click on a link to another page of the TikiWiki.
The message call can be found in footer.tpl
Once the message has been confirmed, it no longer appears in the session.
Before reloading, the values were as follows: