Samsung has started distributing a new update to the Galaxy Watch4 series, including the Galaxy Watch4 Classic. Following on from last month's update, Samsung has brought the Galaxy Watch4 series onto the May 1 security patch. Still, the latest update is approximately a 100 MB file, which is downloadable through the Galaxy Wearable app.
https://www.notebookcheck.net/Samsung-Galaxy-Watch4-Distribution-of-May-2022-begins-for-the-Galaxy-Watch4-and-Galaxy-Watch4-Classic.617696.0.html