Template widgets disappear after save

STR: 

- Create a module and activate it.

- Under Design -> Widget Templates note the two new templates created.  One is for list and one for detail. Both have an MVC designation.  Click on either one and just press Save Changes without making any change.

- Back at the Widget Templates screen note the template is now gone.

Also noted that immediately after the module is created, when you click on the template widgets, the "This template is applied to ..." drop down shows different values that other modules created earlier. For example, a recently created template is listed as "Products - Products - list (MVC)" where as an earlier one is listed as "Promotions - Promotion (MVC).  

Sitefinity 9.1 using Feather.

Workaround - recycle app pool in IIS.