I am working on updating my resume, and I was thinking about changing how I present my prior job title(s). I want to make clear, I am NOT suggesting overstating my title (saying I was a Manager when I was an Associate).
In this example, I want to use "Senior Marketing Associate" instead of "Senior Digital Marketing Associate".
Would this be a problem or issue for you as a hiring manager?
You would indeed be overstating your title. I don't know a hill of beans about marketing, but I can infer from it that your current duties specifically don't include radio, TV, or print. Depending on how much someone else actually reads your resume (it will vary) they might be turned off to learn later at the interview stage that your experience doesn't include these other areas.
Titles do matter. If you didn't want to get stuck in a narrow title, you might have requested the title change when you started the job.