Are there any limitations regarding length of code? Codepen started acting strange and stop executing everything I enter from one point (not even a comment)
This could be relevant:
Maybe disabling auto-updating preview can help.
That didn’t solve the issue… Thing is still the same. Cursor jumping couple of lines when pressing enter, stil not accepting code
Your pen’s working fine here though.
I don’t think this will help but try opening your pen in a different browser or in incognito.
Your best bet could be contacting codepen support.