Instructions:
1: Unlock Widgets (e.g. right click on desktop >> unlock widgets)
2: Click on the cashew in the panel on the top of the screen
3: There appears a screen-wide pop-up: click on 'screen edge' and drag to other screen edge
4: Lock widgets again (don't forget that please

)
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If the task bar widget is gone from your panel:
1: Unlock Widgets
2: Click on the cashew in the panel
3: Select 'add widgets' >> double click on 'smooth tasks' or another tasks-widget that you like
4: drag the tasks-widget to the desired place on the panel
5: lock widgets again
Hope this helps...
(if this was not what you mean, please post a screen shot)