If you go into a code block and select the text and then scroll, visual artifacts appear in the selected code.
Longer code blocks seem to have more artifacts. Scroll off the screen and back a few times and you should see them.
If you go into a code block and select the text and then scroll, visual artifacts appear in the selected code.
Longer code blocks seem to have more artifacts. Scroll off the screen and back a few times and you should see them.
I added workarounds for this in Marked 3. If you're on the beta, please let me know if the issue is resolved for you.