There is significant confusion around 'Title' vs 'Summary' e.g. Solved: Meaning of Description, Summary, Text.. etc. (atlassian.com) in part i believe this is because within a Jira ticket, 'summary is placed where universally you would expect to see a title... (at the very top)
Further, this is more of a problem especially in Roadmaps where this uses 'Summary' field rather than the Title - Summaries are typically sentences or paragraphs long, and are completely not suitable to identify Issues in a ~1 inch space on a gantt chart. This should really be 'Issue Title', although i suspect the difficulty will be because you have names the fields 'Epic Title', 'Story Title' etc. which makes it more difficult?
My suggestions are therefore:
1 - allow configuration of the Title to be used within Roadmaps, rather than default 'summary'
2 - allow users to place 'Title' at the top of the page, and summary to be placed above 'description'