Not a glitch.
You can get some good combos for specific dragons by viewing the specific threads .
Post 7 on the dragon guide has a list of the Dragon threads.
https://forums.storm8.com/showthread....ory-Game-Guide
There is also a color chart on the guide that can be helpful.
For general breeding combos see this thread
https://forums.storm8.com/showthread....stions-Part-II