Go to a gig, create a FAQ, add a answer that hits precisely the 300 characters. Use some special characters such as Enters, slashes etc. Press save.
Be greeted by a big rejection message, for exceeding the 300 character limit.
My assumption is that this occurs due to encoding of special characters, leading to character doubling of special characters. Leading the backed to believe the 300 characters are exceeded. However the front end counter does not give any such indication