This should not be difficult to understand.
We get crucified with Christ when and only when our “
old man” is crucified. (Romans 6:6, see below).
So, When was Paul’s old man crucified? Was the old Paul or the new Paul who persecuted Christians?
Certainly, Paul’s old man was crucified
after his encounter with Christ in the road to Damascus.
“…knowing this, that our old man has been crucified with Him, so that the body of sin might be destroyed, and we should no longer be slaves to sin”
So
@civic and
@Johann are right. In Galatians 2:20 Paul was describing his present condition… a condition that didn’t exist before his conversion.