Maybe it's a compatibility thing between the Dahua and your network setup. Have you tweaked the Dahua's network settings? Testing with other Dahua/Hikvision cameras could give a clue.
You could try setting up a server-side script to fetch the camera feed without the X-Frame-Options header. Or, consider switching to a camera system that doesn't have these restrictions.
Stick with static IPs if you're comfortable with them and already have a system to track them. If you're okay with managing by MAC addresses, DHCP could offer more flexibility.