I schedule an automation follow up email for 7 days after and it scheduled 3 days after the first instead

I schedule an automation follow up email for 7 days after and it scheduled 3 days after the first instead

I sent you an automation email series and I scheduled the follow up email 7 days after joining the mailing list but I got a second email 3 days after joining the mailing list...does anyone else have this problem and know how to fix it?