Bug fixes on Drupal (9 and) 10 to get them to behave...
Every time I upgrade to the latest Drupal 9 release, currently 9.5.x, the following know but not yet corrected patches must be fixed:
Core: Issue #3270647 (Fixed!)
MIME mail get crippled due to an error when creating the headers. #3270647.
Core: Redirect to https and none www
The .htaccess file must be fixed to define canonical pages (a Google term). Make sure http is redirected to https and that www. is stripped from the main URL.