Not able to save Snippet in WordPress backend

Hello,

I have a problem with saving Post/Page Title, Meta Description and Keywords on backend with disabled Gutenberg by the functions.php:
// disable Gutenberg for posts
add_filter(‘use_block_editor_for_post’, ‘__return_false’, 10);
// disable Gutenberg for post types
add_filter(‘use_block_editor_for_post_type’, ‘__return_false’, 10);

https://imgur.com/a/A5N8gJi

When Gutenberg is enabled, it works very well in right sidebar.
I use Elementor Pro with Hello template. Inside Elementor editor it’s OK.
With view the source I can see changes in code, but not in Worpdress backend.

Only problem is with Classic Editor.
I tried to disable all plugins, nothing changes, the same problem.
All plugins are updated.

Thanks

Best regards,
Lukas