Impossible to customize the template

Hi,

I have a strange issue:

the plugin works as expected, but I’m unable to customize the page displayed using a template file.

I created a 410.php template in my theme folder, and it seems detected by the plugin (as indicated on the admin page):
“A template file 410.php has been detected in your theme directory. This file will be used to display 410 responses. To revert back to the default message, remove the file from your theme directory.”

But, the page displayed when a 410 is returned is still the default raw message.

Do you know if it could be linked to wordpress core (I’m on the last verson 4.8.2)?

I use pretty much the same template as for 404 which works… I simply modified the text displayed.

I willing to hook the wp_410_response action instead but should my function return the html code of echo it?