"Correct highlighted errors" but there ain't any

Allen wrote

the three most common reasons are:

• You copy and pasted content from somewhere else (Microsoft Word, another website etc)
• You use Microsoft Editor, the editor changes the html in the editor window to let it highlight, underline or display information to help you improve the grammar and spelling of your post.
• You use Grammarly, for the same reasons as above

And for the record I've done none of those. That was the whole point. All texts were entered directly, and the only formatting that was done was done using the tool bar in THIS forum. These things: 

I don't understand how Safari could be a factor, although I'll accept that assertion, but I want you to understand that from the point of view of this user, it's this system telling itself that an error has been made.

Also for the record, it hasn't happened recently, and I'm not losing sleep over it anyway....nor should you. But I do want you to hear the experience of this user because I doubt I'm the only one.