This is a bad place to be. You’re working hard. You’re creatively finding solutions to company problems. The developer next to you gets kudos just for doing their job, while your hard work and great ideas get ignored, and you get branded as being unreliable. The reason is simple – no matter how valuable you believe your side projects to be, your manager, business partners, and coworkers are depending on you for something else. If you aren’t delivering your assigned tasks on time and with a high level of quality, then anything else you’re working on is going to be ignored at best, seen as self-indulgent at worst.
It’s hard to find good career advice for software developers. This piece, which I’ve read half a dozen times, really is excellent start to finish. I’ve forwarded it around at work, bookmarked it and plan to share it when mentoring. Highly recommended.