Please create bug reports for this plugin at https://github.com/mantisbt-plugins/Snippets/issues
When doing this, provide some more information, e.g. the PHP version you use and the operating system.
Furthermore run <yourMantis>/admin/check/index.php and fix any errors and warnings you might get.
Check also your web server logs and the browser console for errors and warnings.

@Silverhand, for the record we've been using the Snippets plugin on this tracker with 2.26 code for many months without any issues, so the problem is most likely specific to your environment.

I use php version 8.2 from version 2.26. Everything works on version 8.1.