Business settings often elicit a certain level of seriousness. This is because formal attire, formal language, and formal attitudes are viewed as “professional”.
This type of culture will persist in many spheres, but it doesn’t mean that all “business” is this way.
If you are, by nature, a humorous person, question if you are holding that back in situations where you are trying to be “professional”.
If you have to restrict yourself around certain people, ask yourself why you’re trying so hard to work with those people at all.