This question was prompted by the sign-up of researchgate, which has three sections for new users; Academia, Corporate/Government/NGO, and Citizen Science.
If I am being paid to do research, regardless of my skill level, then I feel this makes me a "professional" in my field. After all, it's my primary source of income and my "profession". I would count myself as an "amateur mathematician", however the term "amateur" implies I'm not being paid for my work. This work is my livelihood, even my skills are far below that of a genuine mathematician.
However I am also investigating a wider range of topics than my training, and it involves fields where I am unable to make any contributions however I am studying those fields and even writing small literature reviews for in-house/corporate use.
While I feel it is fair to claim I am a "blockchain researcher", when I am investigating fields for my company which may have applications but I am currently unqualified in, should I count this investigation as a part of my profession or closer to recreational activity?
While I am being paid for this rather than it being purely recreational, it is still a field which I am not at the frontier of nor deeply knowledgeable of.