Editing WordPress Widgets in the new Block editor is not for the faint of heart, Classic Widgets offers a remedy
Classic Widgets is an official plugin managed by the WordPress team that restores the previous («classic») WordPress widget settings screens.
Once enabled, this plugin restores the previous elements for editing the widgets and disables the block editor when managing widgets. A further configuration is not necessary and is not provided, the classic widget elements for the design are activated or deactivated by activating or deactivating this plugin.
The design of widgets in WordPress is now possible again as usual, the difficult to master and confusing block editor for widgets does not have to be used further.