Superworm Breeding

I'm trying to get a superworm colony going but I'm running into a problem. I have 3 adult beetles and about 8-10 pupa right now. I have no problem getting them to pupate or even turn into beetles. The problem is when they become beetles. Its like they slow down and don't move around much. They flip over on their backs on a daily basis and I have to go in and flip them back over. They are on a bed of oats and are given carrots, apples, etc. for moisture. This morning I think I found one of the beetles dead. He didn't even turn black. Just went to a dark brown and died.

Any thoughts on why my beetles are failing to thrive? My mealworm colony is starting up now and I've got close to 50 pupa and just got my first beetle this morning. Mealworms are easy. I don't think I'll have a problem breeding them, but I just don't know how to get my superworm beetles to survive. The other 2 beetles are still alive but not very active.

Another beetle just died. I'm going to try changing the bedding from oats to wheat bran and see if that makes a difference. One of my pupa turned into a beetle so I'm up to 2. They keep flipping themselves over on their backs. Any thoughts?

I never tryed it, but see all kind of advise on how to do it on line, I would look a few over see if you overlooked something.

As far as I can tell from the information on google, oats are fine. The room never dips below 72 and mostly stays around 75, so the temperature is fine. I give them fresh veggies or fruit once a day. I've been using apple and carrot as I have a lot of it around but the websites seem to favor potato, so I'll give that a try.

On the bright side, my mealworm colony is doing wonderful. I have over 50 pupa and I'm taking about 10-15 new pupa out of the worm bin a day, sometimes more. I'm up to 4 beetles and all are doing well. If only super worms were so easy.