Corn cob isn't recommended as a bedding - and yes it can cause issues. Beech chips, cork granules or coco fibre are all safe ones, although you have to ensure cocofibre isn't too moist.
We were considering corncob as a dig box medium, but ultimately went with cork granules. She seems to enjoy digging in there to find a few seeds mixed in daily.
Now, have another situation going on I'm hoping someone can shed some light on. This is a bit long - apologies in advance. To give some background, she first started being more interactive maybe 8-10 days ago. For 3-4 days she was coming up every day at feeding time and letting us pet her, maybe a little lifting, but she didn't want to stay in your hand for more than a couple seconds, squirming out. Not very keen on being turned on her back, while in hand, either (as we've seen in some videos). She'd still hang out on the 'top floor', letting us pet her. Then a few days of avoiding us, sometime after me vibrating the cage a little as she was incessantly trying to chew through the stilts for the multi-chamber (she's about 1/2 way through a 1-1/4" stilt, and so I'll have to wrap in metal or similar).
Anyhow then she was out again for a few days, and another day or two hiding after some spot cleaning (we're not sure where she is sleeping now, and haven't found her recent pee cache) and after offering her a tube and bringing her to a 'playpen' box (maybe 30" x 24") with some obstacles and treats (she definitely got nervous being there and we need to add more to the box). But, we haven't really had her out on the floor or anything... house is currently being rebuilt, and there's all kinds of trouble to get in for permanently being lost. But, we will setup some barrier system and do that.
The last few days that she's been out of burrow and up-top, my daughter and I would open the cage lid, and pet her a little. She then started going to the two corners where the top opens - where the multi-chamber lid is (5" from lip of open cage) or where the sand box with lid is (about 6.5" from lip of open cage). And of course she proceeds to try to climb out. Her little paws over the lip of the perplex, and lifting herself up. So I grab her and reset her elsewhere in the cage. She runs back and does it again. And again, and again. Tonight, she was quite fast. She even climbed up my arm, thinking it was a ramp out of the cage. Then I gave her the tube and put her in the playpen, and she got nervous, looking for a way out. BTW, she doesn't have a problem doing full body weight pull-ups, even off my arm

Of course, if we take our eyes off her for a minute, she could be up and over the lip of the cage, and down about 4' to the ground, which wouldn't be good. On some of these nights, after attempting to 'escape', she just sits and stares intently at me, 25' away.
I can't figure out if it's just a game to her or if she genuinely wants to escape. Today when I shut the lid, she did a chew or two on the 23ga stainless hardware cloth that I installed on the lid (she can just reach it on her hind legs from the top of the multi-chamber). Of course, I told her multiple times 'no', and blew some air at her each time. Eventually she stopped. Maybe she just wants out of the cage for playtime without a playpen. Or, maybe she will chew through the stainless wire and escape overnight.
Anyhow does any of this sound familiar/expected/concerning? Any input is great.