Tapping a "mailto" opens K9 in a new browser tab

[WK]

Hello,

when I tap a "mailto" link on a web page, K9's composer is not opened as a separate app any more, but as a new tab inside the browser. I haven't done any changes to the system settings on my tablet for a long time now, except for updating the apps. Furthermore, this strange behaviour happens on all my devices now, regardless of the installed OS and browser in use. So I think it must be triggered be the latest K9.

How do I get back the old behaviour? This new behaviour is most inconvenient, because I can not switch between the composer and the browser while composing the mail.