Do you have a visual barrier between the 2 cages. They should not see each other as it will stress them out. I have my enclosures side by side but have a white vinyl shower curtain between the 2 so they can't see each other.
Other things I would question with what you have posted.
1. Mealworms are not a good staple food for your chams. You should vary their food: Crickets, silkworms, hornworms, dubia roaches are all good choices for feeding. Make sure they are well gut loaded with fresh fruits & veggies (and commercial gut load if desired, not flakers cubes)
2. If they are adult their basking temperatures could be a bit warmer I think (I do not have Veiled so someone feel free to contradict me, I think the female could be cooler, which may be why she is doing better)
3. Maybe you could put the enclosures up a bit higher. I know they like to be higher than those around them.
4. If the UVB light is >6 months old (or you don't know its age) you should probably replace it.
Make sure you are supplementing correctly by doing some research here on the forum. Make sure you that your daily calcium does not have D3, it should not be used daily but just a few times a month. They should have plain calcium daily.
You really should invest in a thermometer and hygrometer to monitor temps and humidity. You can purchase an infrared temp sensor for a reasonable price that will allow you to check the temperatures at various places in your enclosures.
If the male is an adult you may not be able to change his aggressive behavior. Try to hand feed him, I would recommend using tongs and not being above him. Just be slow and persistent and you may have success in time. Many, if not most, chameleons are not particularly personable. I have one that is and one that isn't..
Good luck with them both and welcome to the forums!!
Here is a link to the Veiled chameleon care sheet that will help you with correct temps and food etc.
https://www.chameleonforums.com/care/caresheets/veiled/