Please state in which country your phrase tends to be used, what the phrase is, and what it should be.
Example:
In America, recently came across “back-petal”, instead of back-pedal. Also, still hearing “for all intensive purposes” instead of “for all intents and purposes”.
It’s definitely a mistake, but I think it has slipped by because spell check wouldn’t have a reason to mark it, and not everyone uses grammar check, so they think it’s correct to spell it out by the sound of the contraction.