Are we not able to get back to a level after we leave it?

I had a chest that was locked and didn't open. There was a magical thingy that required a knowledge arcana check which I failed. These were on 1st level. I went down to the next level. When the characters made 2nd level, I tried to go back up the stairs to check the chest again and the magical thingy, but I ended up outside of the dungeon. When I went back into the dungeon, I ended up where I had left the dungeon from. This will be nice when I want to leave to rest or sell loot and buy stuff. But right now, I just wanted to see if I could find out what I missed when I failed my die rolls.

I download and installed fresh yesterday afternoon (version 2.0.3). Installed Beneath the Stolen Lands DLC. No problems. I have been away from the game for a few months. The BtSL DLC sounded like fun and I wanted to try it.

In the main game, I have not progressed very far. I was frustrated with the kingdom management and especially the pacing. It took me by surprise, because I had been running the adventure path for some friends and it definitely had a slower pace. It recommended giving the players a few years of game time to develop their kingdom before the real troubles started.

I have still enjoyed the game. I have started 14 or 15 main characters to experiment with different classes and character builds. I have taken several of them through the demise of the Stag Lord, but only the first one has moved on to chapter 2. I think with the changes than have been made to kingdom management since last fall, I will start one of the other characters on chapter 2. Or maybe start another character from scratch and get there with them.

Yes, the floors are self-contained. Once you go deeper, you can't go back. Either save-scum or have multiple people with trickery. Same applies to perception.

Thanks, InEffect.
By the way, I liked your various character build postings. I was trying some of those out in the 14 or 15 characters and their companions I mentioned above. They also gave me a new perspective on multi-classing in the PnP version of Pathfinder.
So thanks for those, too.

I really wouldn't apply most of it in pnp. Things like that don't fly at the table for the most part and your DM will hate you for going above the curve with cherry-picking multi-classes. Unless you play with a wargaming DM, then anything goes xD
Games like PK are fun in a way you can do here what no sane DM will ever allow. Things like thug kineticists. I generally enforce 3 before 20(3+ levels in any taken class before 20) rule at the table for that exact reason.

Damn. I've been looking online for this exact problem. Not only did I want to come back to retry checks I've failed, but I also left loot hanging around assuming I can pick it up later. They really should change it.