It seems that the marked library by default is wrapping the content it processes with pp tags (at least, for me). Following this and checked out this (but the questions and suggestions are all quite old).
Also there is a claim in 2023 on the Github issue that “this issue has been resolved,” with no explanation of what that means (still happening for me – I am using https://cdn.jsdelivr.net/npm/marked/marked.min.js which currently says v14.1.3).
One user on the Github issue suggested I use marked.parseInline…. However this seems to remove all line breaks from the content, not just the outer wrapping p tags that marked seems to be adding.
Anyone know how to remove just the outer tags, while preserving intended line breaks in the content itself?