Grammar Tools Redux

Things I've seen from Grammarly:

Imagine part of a sentence, like this:

...it was the end of the week, so they would...

Grammarly now enters confused mode, then announces that the comma was unnecessary. So I delete the comma, Grammarly then promptly underlines the word week in red and tells me there should be a comma after week. add the comma, and we are back to where we started, with Grammarly telling me it is unnecessary... Sigh. My solution was to put a period after week, delete the word so, and capitalize the word they, at this point, Grammarly was all happy...