I’ve had many job titles over the last 18 years. I prefer to use the word Designer.
I focus on doing the right thing at the right time rather than obsess over job titles.
Separating design into specific sub-disciplines like Product, Interaction, Service, Content and even User research (which is a design discipline) is helpful when working as part of a team. However, in general, those words confuse people who are not designers.
When working as part of a team, it sometimes helps to distinguish between disciplines. But we should not let this get in the way of doing the right thing and delivering value to users.