!!! MS Teams in its most recent versions started to use the default notification system, so this patch is not needed anymore.
Tested fixed versions of MS Teams > 1.3.00.25560
Patch to fix Microsoft Teams notifications problems in dwm window manager.
Microsoft Teams uses its own notification system that vanilla dwm do not handle properly. This patch do not want to encourage the use of Microsoft Teams since it is proprietary software. However, in many working environments it is the main teams communication software, so in the case you must use Microsoft Teams, this patch can be handy.
To apply this patch, run:
curl https://raw.githubusercontent.com/save196/dwm-msteams-fix/master/dwm-msteamsnotificationsfix-20200912-3857c41.diff | git apply --reject
from your dwm folder, then rebuild and reinstall dwm.