How Conservative Is Your Company
If all of the senior executives at your company wear a suit to work, are clean shaven, and have short hair then the chances are this is perceived as the right look for the company. You don’t even need to ask the question are beards unprofessional?
If the clean shaven in a suit look isn’t one you want to emulate that’s ok. If you enjoy your job and are happy to stay at the level you are then great. If you want to move up however a beard might hold you back and you may want to look for a role in a less formal company