How to stop the phone's adress book asking for synchronization with Messenger contacts?

I am using a Galaxy A41, Android version 10 maybe (honestly i can't make sense of the version indications in the Software information tab.)

Recently when i go to Phone -> Contacts (or Address book, i'm not sure of the translation) ; the phone will randomly display a popup asking me if i want to synchronize my phone contacts with my Messenger (im guessing facebook messenger) contacts. I don't want to do that ever, and i don't want to be asked for that.

Is there any way I can stop that popup from ever showing up ? I tend to use my contact list a lot, and it's becoming annoying to have that invasive and unwelcomed functionality trying to force itself upon me each time I want to make a call. I already tried to got to Settings -> Accounts -> uncheck Automatically synchronise datas (i don't use that at all apparently).

Thanks ! edit : Here is a screen capture of the popup - name of phone contacts are blurred for privacy concerns. The popup reads : >

" Activate Automatic synchronization ?

To synchronize your > contacts and keep them up-to-date on all your devices, activate > Automatic synchronization for Messenger.

Cancel | Activate"