Unsubscribe bug due to filtrer campaign reset

My PHP version is : 7.4.19
*My MySQL/MariaDB version is mysqlnd 7.4.19
Mautic 4

My problem : I had a segment (let’s call it segment A) with filters, by mistake I added another filter that excluded a big part of the contact. So I deleted this filter and all the contact went back in the segment like it used to be.

I precised that we didn’t modify our unsbscribe page.

The thing is some contact that receved an email before the filter incident unsubscribed to everything.

After the segment A correction (the contact went back), I sent the campaign as usual.

Several contacts still received this email even if they unsubscribed before… I don’t know how is that possible knowing that they did unsubscribed.

Should I create an automatic rule in the campaign or somewhere else to make sure that contact that did unsbscribed to everything won’t be contacted ever again ?

Thanks !