Yesterday Jetpack 5.2 was released which unfortunately introduced a bug that prevented content in new widgets from being saved. The issue did not affect existing widgets, only newly created ones.
Thanks to prompt reports from our users we’ve released an update (5.2.1) which fixes the issue.
We apologize for the inconvenience and recommend you update now.
Thank you to the contributors to this release: Rocco Tripaldi, Miguel Lezama, Derek Smart, and Elio Rivero.