Puppy used to love pen but seems to hate it now- seeking tips!

So we started off our bernedoodle puppy (got at 8 weeks and now 11 weeks) in a play pen with a crate attached. Everything happened in the pen and it was great! He LOVED it and it was his safe space.

We have now moved the crate outside of the pen and upstairs to a quiet area and he's finally getting 16+ hours of sleep! Crate is zero issue. However, he seems to be hating the pen! We sometimes tether him outside the pen- either right outside the pen (with the pen door open) or in the living room while we're on the couch. 99% Feeding happens in the pen, water is in the pen, toys are in the pen. But he hates being in there and bangs on the door and gets all antsy in there. But the moment we tether him outside the pen, he's usually okay OR if I sit inside it with him to do training (settling, sitting, leave it, etc).

We are getting another crate for the pen. We need to start training him to be left alone in the pen while we're out and he's awake. I would love some tips on how to move towards this- since I feel like we've gone backwards in the pen!

• First theory is that he has bathroom anxiety and fears that someone won't take him in the bathroom because he can't see us? He hasn't had an accident in the house in two weeks.
• Second theory is he has separation anxiety and just wants to be with us. He acts like he hates the pen even if we sit outside of it. However, if we're inside it he is fine. Third theory is a mix of the first two
• Third theory is both theories are true