No, I don’t believe they can.
But I believe you said all your future sins are already forgiven. Yet there is that unpardonable one.
What I would conclude according to your theology as you have presented it is:
All your future sins are already forgiven, unless you commit the unpardonable one, in which case you don’t have the Holy Spirit living in you and therefore you lose the forgiveness for all your past, present and future sins that you once thought you had.
You are not making ANY sense.
Does the concept of being adopted into a family escape you? Do you disown your child and write him out of your will every time he does something wrong. And then reinstate him only when he repents?
Is he still not your son even when disobedient? Does the disobedience actually sever the relationship or only interfere with the lines of communication?
God is not going to send any redeemed child of His to hell just for not being perfect enough so as to miss repenting of a sin they failed to realize they committed.
And Catholics wonder why the God they portray comes across as capricious? It's on again/ off again salvation, all based on human effort.