Task widget in Bliss shows events but not tasks

My tasks are on Murena nextcloud on three separated calendars.

I can see them all on my first phone and my second one both with /e/ and the forked app “tasks”.
I can also see them all on thunderbird on my linux boxes.

But I cannot see them where they are most needed, i.e. on the widget which reports only calendar events and not tasks.

And this happens for Bliss widget, for lawnchair widget and for todo agenda widget.

Am I missing something obvious here ? Is there something that I should activate ?