When my creative work is too easy, too often. Prima Donnas like many creatives are me)
If you really want to be creative, you must challenge yourself. If the job is too easy and you can do it by rote, your creative self will refuse to get engaged. Conversely, a task that is too hard will discourage your latent creativity and make you want to give up.
If your job is in fact easy, find ways to add a bit of a challenge to it. You will find that the quality of your work will greatly improve and you will enjoy the work more than you have in the past. If the job is too difficult, take a step back, lower the bar a bit or break it down into smaller segments.