Multiple reception of notification email


We encountered a problem with some mass sent of notification email when a meeting with multiple participants is created.

Example here where the meeting “[Léo] Point Infos Projet” sent multiple times to one (maybe more) persons but not every participants !

More exemple, in french : Réception de plusieurs mails d'invitation

Moreover, there’s some strange points about the notification as you can see in the screenshot below :
the sender is an user (thru Nextcloud aka “Le Nuage”)
but the field “answer to” is a mix between the name of the sender and the email adress of the organizer.

Do you have any idea why is this happening ? Is this a misconfiguration on our side or a bug of Nextcloud ?

Config informations

Nextcloud version (eg, 20.0.5): 25.0.2
Operating system and version (eg, Ubuntu 20.04): Debian GNU/Linux 11 (bullseye)
Apache or nginx version (eg, Apache 2.4.25): nginx/1.18.0
PHP version (eg, 7.4): 7.4.30