I’m fairly sure you are mistaken on this.
Thats a little complcated. When a baby is baptised, they are (obviously) below the age of reason. They are batised based on the faith of their parents. Therefore, the sacramant IS valid, and they have been washed of sin and entered the covenant family of God. Yet, since mortal sin can seperate man from God, and since a person can willingly throw away God’s free gift of salvation, this person can still be damned if they choose such a path. Baptism is what it is: The washing of sin and the entrance into the covenant family of God. It is NOT a guaranteed ticket into heaven.
Confirmation, on the other hand, deals with a person who HAS reached the age of reason. At the ceremony, the Bishop leads the renewal of baptismal promises. Here, the candidate MUST REPEAT the Baptismal vows of rejecting Satan, accepting Christ, etc… IF the candidate is LYING about all that, then the confirmation is invalid.
I’m 99% sure I’m right about all this