Be aware of the behavior the list templates are not available on Office 365 group sites.
I assume the list templates are not available on Office 365 group sites now.
The error has been occurred when creating a template of the questionnaire app and deploy to the site. There are many opportunities to create and operate the Office 365 group sites by public users, so that I hope the feature will be implemented that any list templates can be available for all users.
The ability to save a list as a template hinders collaboration and the ability to reuse for creating no-code business application in SPO. A modern Communication site has the save as template option in site settings as should the modern group connected team site.