If you're using markdown a lot with vim, you may have run into an issue with formatting. After you type a paragraph, then go back to edit, the auto softwrap that happens, gets off when you add or delete text.
This used to drive me nuts, until I found a simple fix.
reformat the line and reset the wrapping. Most of the time, you'll need
to fix the whole paragraph because any edits typically effect lines and
words afterwards as well. So, you can select the whole paragraph and
I ended up mapping this to a shortcut:
# .vimrc map <leader>al vipgq