Error Entity/field definitions Mismatched entity and/or field definitions

And create node and save display next error:

Deprecated function: preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in Drupal\pathauto\AliasCleaner->cleanString() (line 197 of modules/contrib/pathauto/src/AliasCleaner.php).
Drupal\pathauto\AliasCleaner->cleanString(Object, Array) (Line: 348)
Drupal\pathauto\AliasCleaner->cleanTokenValues(Array, Array, Array, Object) (Line: 263)
Drupal\Core\Utility\Token->doReplace(1, '[node:title]', Array, Array, Object) (Line: 189)
Drupal\Core\Utility\Token->replace('[node:title]', Array, Array, Object) (Line: 228)
Drupal\pathauto\PathautoGenerator->createEntityAlias(Object, 'insert') (Line: 381)
Drupal\pathauto\PathautoGenerator->updateEntityAlias(Object, 'insert') (Line: 86)
pathauto_entity_insert(Object)

PHP 7 and lower just would ignore the missing parameter, while PHP 8+ displays the warning. It may also vary with your environment / debug settings.

#3 the problem is that it does not generate the clean link that should be example.com/page-demo but it generates it as follows example.com/pagedemo as you can see it doesn't replace the space with the hyphen

Changing back to "unassigned"; as a reminder, once you're finished with your work, or are not able to follow up on it, please set the "assigned" field back to "unassigned" so that others know they can continue your work. Thank you.