BTW …I’m not a vet…just speak from years of experience keeping chameleons and many other lizards and reptiles…and from reading a lot.
You said…”the last clutch she laid was in June she said I think 20ish eggs”..if the last eggs were laid in June, then it’s too soon to be laying another clutch…so I’m suspecting retained eggs. There are a few reasons for retained eggs. It could be a move towards egg binding and follicular stasis or it could be deformed/fused eggs or a number of other reproductive issues…but it’s not normal.
You said…”So it’s not normal for them to pass underdeveloped eggs and then go on and lay a clutch after?”…not normal.
A visit to a good chameleon vet and an X-ray would be a good idea IMHO, to see if she has an issue.
@Beman mentioned the casque, etc….and inagree, there may be some other health issues going on.
Do you use a vitamin powder twice a month with a preformed source of vitaminA?
You mentioned underdeveloped eggs, do you have a photo of them? Why do you say they are underdeveloped?