MacBook can connect to external monitor AND a Wacom One tablet using Monterey but not using Ventura

Under Monterey I could connect my MacBook Pro (2019) to an external monitor (3440 x 1440) *and* to a Wacom One tablet at the same time using two USB-C ports. After an upgrade to Ventura, I can connect *either* to the Wacom tablet *or* to the external monitor, but not to both. If I add the second external device, the system tries to configure the screens, and tries, and ties,… Any idea why this happens and how to fix?