I want to change the default template for my pages to a template called
I have seen this question posted and answered for pre-Gutenberg Wordpress, but I have not found a working answer for Gutenberg Wordpress (version 5.3.2 at the time of this question).
This is the non-working answer I found. When I try the non-working answer the template is set to
fullwidthpage.php but when I try to update the page I get a message that says "Updating failed."