1st off. i some how ended up with Addler in my party without recruiting him near the end of world 1

then just now. im in world 2 and i go to recruit Addler.  I exit the castle. and PLOOP im in world 1 lol summoned black chocoboo, he summoned but he doesnt move.  thankfully i saved right before addler.

I got exactly the same thing. Addler appeared into the party out of nowhere and the world crossing. lol

In the end, I cannot recruit Addler and wonder if there is a way to do it...?

I think to not have this glitch you have to recruit him when you retake branch before going to ivalice.  After beating Hans you go outside and to the left is a portal. Beat the dungeon and you get him the first time which I assume unglitches him in merged world.  I assume this can be done at any time before merged world or wherever he was forced into your party

You're not the only one who encountered this glitch. Apparently there's a "check" of some sort that needs to be put in place.

Hoping for an update that fixes this soon! I haven't been able to continue playing for about a month now because I saved inside Branch Castle. 😭