This issue you’re experiencing — where capital “I” and lowercase “l” appear bold after editing a PDF — is often due to font substitution or font rendering issues in Adobe Acrobat. Here’s how you can troubleshoot and fix it:
Sometimes Acrobat substitutes fonts during editing if the original font isn’t embedded or available on your system.
How to check:
Open the PDF in Adobe Acrobat Pro.
Go to File > Properties > Fonts tab.
Look for the font used in the document. If you see “substituted” next to it or if the font is missing from your system, that’s likely the cause.
Solution:
Try replacing the font with a similar one you have installed.
Or embed the correct font using a PDF editor (if you have access to the original font): https://adobe.ly/3Esf9Hw
p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.