Use a Markdown preview after structural edits. Check heading order, paragraph breaks, lists, links, images, tables, and fenced code blocks. A missing blank line or fence can make several sections render as one.
Click important links, inspect image alt text, and verify that code is not accidentally interpreted as formatting. If the publishing platform uses a different Markdown dialect, preview there too; tables, checklists, and embedded HTML may render differently. Finally, read the rendered page from top to bottom at phone width.
The raw syntax can look correct while the result is hard to scan.
Akousa