This has always been a problem it seems. Microsoft now handles grammar and spelling themselves, but originally they licensed software called CorrecText.

This article from when CorrecText originally released in the 80s, https://www.nytimes.com/1988/03/06/business/the-executive-co..., ends with discussion saying "One big problem in designing Correctext,... has been 'overflagging,' or excessive sensitivity to minor errors."

Seems like that problem still hasn't been solved...