I just got some black soldier fly larvae for my beardie to try, I put a good amount in the bowl and she eats them within minutes, but I noticed not even an hour after eating them she took a poop and I saw a live one squiggling around in there, what is causing this and what can I do to prevent
It's probably just because she poo'd so quickly after eating i'd guess. They don't always really chew the BSFL since they are small and soft.
Was this the first time she has had BSFL? And did she eat a lot?
It's usually best to introduce new foods slowly. The new food in such a large quantity could have slightly upsest her stomach and caused her to expel them quickly.
Keep trying them but in smaller quantities until she gets used to them and see what happens.
As long as your basking spot is the right temperature, and shes able to bask after eating to digest her food, you shouldn't have any digestion issues.