Hawk moth wing expansion problem

I have raised and hatched dozens of moths and butterflies including Attacus atlas at one point but the two times I tried to raise hawk moths (Elephant and Lime Tree) the adults failed to inflate their wings.

I have a pupa overwintering box and this winter a Noctuid and Geometrid both emerged and inflated their wings fine. But the Lime Tree Hawkmoth appears to have just walked around the box and even sadly got stressed and ejected some anti-predator fluid.

When I opened the box it was too late for the wings to inflate. As a female I released her back on a lime tree tree near where I found her in the hope that she may still be able to release her pheromones to attract a mate and lay eggs before dying. In her case she would not have been able to fly and spread her genes, but hopefully would have the chance to complete the cycle all the same. Rather sad.

May years ago I had the same problem with an Elephant Hawkmoth. At the time I put that down to the moth somehow being trapped in twigs in the pupa box. I now put nothing in there in case.

I'm guessing now that Hawkmoths, perhaps because of their large wingspan, have some in built switch to stop them expanding their wings until they are well clear of obstructions. In future I will put then in a large net to enable them to climb far above the ground to see if that helps trigger wing expansion.

With smaller moths you can see the chrysalis start to lighten as the wing form. This appears not to be the case with Hawkmoths as the pupa wall is so strong. Also the pupae don't seem to move either. At least not with my Lime Tree Hawkmoth. So there is no way to tell whether the pupa is still still alive. It must be moved from over wintering to emerging box at the right time of year and left. Earlier if kept over wintering at higher room temperatures, and also moisture is a problem if keep indoors which is much drier than in soil or under leaves. I keep in the garage to try and encourage emergence at the right time of year so they are more likely to meet other moths and mate.