Separation training regression when puppy hit adolescence

Hi everyone,

Our boy is just about to turn 6 months old and we’ve definitely seen his personality shift with starting adolescence. He’s more confident and has an “I don’t care” attitude to our general training (stay, wait, etc.) but we’re sticking with it and following through.

The biggest difference we’re noticing is in our separation training. A couple of weeks ago we could leave him alone for 1.5 – 2 hours and he wouldn’t care much. Now it’s a different story and he’s a lot more vocal when we leave (whining, barking). He has this new pattern where he whines/barks for 30 seconds, goes to his bed (looks like he’s going to sleep) for a minute then gets up and whines/barks again for 30 seconds and repeats this over and over.

Before hitting adolescence he wouldn’t even look up when we left and would sleep for pretty much the entire time we were gone.

We’ve done a TON of work on leaving him alone in preparation of him not having separation anxiety when he gets older since we got him. Progress has been slow but steady for the most part. We were hoping when he reached adolescence he may gain more independence and be able to handle staying home alone longer but seems to be the opposite.

We leave him alone in his play pen, he doesn’t love the crate for being left alone (but sleeps in it overnight and naps during the day in it).

Did anyone else have a bit of regression at the beginning or during adolescence regarding separation training?

TYIA!