My guess is that it’s a quirk created by the tool, as paragraphs are not normally locked. Have you tried to add a new paragraph to the column and then copy > paste the text from the locked paragraph to the new one?
html2bsdesign was made by a private user. It’s not an official part of Bootstrap Studio, and thus there’s nothing in the BSS docs that would cover this. You should probably post this question on the existing thread for this utility…