that's understandable, they can cost a pretty penny maybe in the future you could try them.
that is the reason why the female should be left in the tank even after mating, a lot of breeders take her out after the eggs have been taken up by the father just like we do with betta splendens and that is when the mistake happens. The males tend to be quite nervous when holding the eggs in their mouths so any sign of "danger" (even if there is no real one) makes them swallow them since they think "id rather my eggs become food for me and fuel me than to become food for predators and fuel them" which is something quite common amongst animals.
As such when you scoop the female out the male just witnessed his wife get swooped out by a strange object and so he thinks that with such a "predator" lurking around his babies won't make it anyways so he swallows the eggs. Just keep the female in the tank (since they choose to be life-long partners they will not attack each other when not breeding unlike B. splendens and the female will not attempt to eat the fry once again unlike B. splendens), make the tank species only and keep their aquarium away from doors, windows, hallways, TVs, or any other foreign object that causes lots of movement and noise, and be careful and stealthy when working or being near the aquarium, this should stop the male from eating or dropping the eggs, the same applies for other paternal mouthbrooding bettas like B. channoides.