You’re going in circles.  Put the aggregate back to how you had it (audio interface first).  Adjust the I/O plug-in to output and input to the correct AGGREGATE channel numbers and you’re good to go.  You’re making it hard to figure out what you’re trying cause I still didn’t see a screenshot of Logic yet (get emote out of the way).  And also show your settings for the I/O plug-in as well please.