SMTP settings not saved

Hello,After modifying the SMTP settings (in "Envoi d'emails" under "paramètres globaux"), I save normally. (no error) However, if I change pages and come back, I notice that my settings are again the old ones (the default ones in my case).
Similarly, if I click on the icon to perform a test send, the logs do not indicate my new settings.Thank you in advance for your help.
(PS: the "envoyer les emails comme l'utilisateur courant" setting is set to "non")