Others have given great "general advice" answers. So I'll do a Frame Challenge here.
A different question you might wonder is why you receive unclear feedback from your bosses. As others mentioned, if I'm criticizing someone, I should always prepare a few exemples to support my criticism, this is important both because the other person might not even notice or remember some relevant quirks or past happenings that play a relevant role on making the criticism necessary. I should be able to give clear and truthful examples, but I'll normally delineate with "that's just an example of a recurring issue/characteristic of yours". There are cases when this feedback preparation simply never reaches a concise, professional and relevant message, often they involve me not having good enough examples, or the kind of reaction I might expect from you.
There are a few reasons someone might avoid giving honest, complete feedback about your professionalism:
1. Something happened mid-way an escalating situation.
Maybe you had every right to be mad at someone who wronged you, maybe I'd have lost my temper if I were in your shoes. Nonetheless, it would still have been more professional from you to keep your temper, maintain a normal voice tone and not respond ironically and de-escalate a conflict situation. Learning to breath and letting things pass is an important but increasingly rare skill (both professionally and in personal life).
2. They involve your managers being partially wrong
Take the earlier example, now image I am your manager and maybe I was the one pissing you off. Then, I'd really not be in my rights to further complain about you. It's like your doctor telling you to stop smoking with a pack of cigarettes in his pocket. The message is valid nonetheless, but the messenger himself is not ideal.
3. They actually think you don't handle feedback well.
Everybody has some negative feedback they should hear, you and I are no different in this regard. But if every time I try to give you negative feedback, you bluntly disagree with what I am saying, and I leave with the impression that I've damaged our relationship and there is no hope for an improvement on your part, I'll probably refrain from addressing issues with you directly. In effect, you might be intimidating people who attempt to give you negative feedback.
4. They involve a collection of individually harmless events
Everybody makes some slightly inappropriate joke or comment here and then, or even funny harmless jokes. Calling someone's attention for doing so is just not worthy. But maybe, if excessive harmless jokes disrupt meetings, this reflects badly on you. Maybe something you do has some remote probability of offending someone, but you do such things so often that the law of large numbers is just around the corner before you actually get into trouble. People generally tend to disagree with this kind of feedback.
5. You are crossing blurry lines
Maybe half the people in the office have some small tattoo like a butterfly on the ankle or a peace sign in the wrist, and the company doesn't want to sound conservative by forbidding visible tattoos in the workplace. But you have some big (albeit non-offensive) arm tattoo that could easily be hiding under sleeves, but is almost always on display. Maybe the company has a casual dress code, but everyone suits up for meetings with clients, except for you. So you are not exactly wrong, but your manager has no clear-cut lines to point out when you've trans-passed.
6. You don't communicate with clarity
Maybe you accept every task given to you, but you send an unclear message when being given such task. Sometimes ambiguous sentences like "I'll see what could be about it" is supposed to mean "I'll handle this situation" (this is what your boss wants to hear), but these phrases are also used by people who mean "I'll won't do it, but I need to dismiss this conversation without denying explicitly". Maybe on your job things are not even clear-cut enough that your boss is able to tell afterwards what you've meant. Think about "plausible deniability", maybe many things you say give room to misinterpretation, and this happens so often that people start thinking it's deliberate. It's very annoying to work with someone who talks or acts like this.
7. You complain too much or are too pessimistic
You are in every right not to be cheerful on some idea, and maybe bad things happen to you and you need to vent. It's not exactly unprofessional to complain when chit-chatting nor to express negative opinions. But if those come from you way too often, you cross the professionalism line. I've heard about the experiment where you are challenged not to complain about anything at all for a week, it is said that once you do it, other people's rants become unbearable to you, and that may be how other people are perceiving you. However, coming from a manager, this advice might sound cynical and maybe censoring, which again is something a manager should avoid.
8. You disdain rules
If some new rule is announced, and many companies are full of "someone screwed up something, so now we have a new rule in place...". Maybe you are often heard short afterwards mocking the rule or its announcer. You (maybe unintentionally) send an ambiguous message that you might not follow the new rule, and maybe you are motivating others to join you. This both shows a problem with authority (which managers want to earn, not demand), and also creates a dilemma for rule makers: "Do I censor this guy, or do I wait until he breaks the rule?".
9. Maybe you don't understand authority
If the company's CEO or whichever else big cheese asks for something, in most conditions, you do it. If you direct manager asks something, you should negotiate the terms and generally do what you've been asked or respect what was "suggested" ( i.e. imposed) to you. Exceptions will always happen but should be exceptional, not the rule. Nobody will enjoy coming to you and explaining this, and no manager will constantly threaten you with his actual authority-granted powers (i.e. firing you). Also no good manager will tell you do act without question, but you might be overdoing it because you just don't get the spirit of the hierarchy dynamics within the company's culture. I've seen a place were people had a really hard time informing a high-level executive that a big event had long being scheduled to a given date after he wanted to confirm a two-month earlier date during a meeting. Stupid as it sounds, if you were in that meeting in that company and just said "the event has always been scheduled for X date", you'd have done the textbook procedure on how to handle the situation, but in that company, I would expect people to think that you simply don't understand authority (and I myself don't understand them). Yet, I doubt someone would have the nerve to be honest about it to you.
