When creating/editing a newsletter the Text & HTML blocks are not always showing handles to edit, clone or delete. If they do & attempt to edit, the changes are either not saved or defaults to showing the whole home (front) page inside a block with no handles. All other blocks appear to be working correctly in the composer.
Using Chrome & Firefox, Version 6.9.7 of Newsletter, WordPress 5.5.3 PHP 7.4 Tried disabling all other plugins with same result.