I have the same situation. Mine are both fixed. I just say no to the male. He stops. I think they become jealous of each other.
I know people who have had great success using shock collars for this type of situation. Unfortunately, if the male can't be trained to behave, one of the dogs may have to be rehomed. Misfit Clinic may not be your best resource for this situation, as they are primarily a place for low-cost veterinary care and spay / neuter. They also Place identification chips in pets
Need to talk to a vet and make sure they are both healthy.
Thanks! Your answer is awaiting moderation.