Oh, I'm definitely not telling you anything is wrong. I'm aware of the voice leading conventions of the style (although I may not like them sonically sometimes), and I'm not gonna harp on you on that.
It's a combination of the harmonic rhythm and the idea behind the harmonic sequence that you start and don't finish (sequences, as I'm sure you know, are still a thing in this style). For most (big emphasis) of the music up until this point, a bar has been split into 2 and 2 harmonically, or left as 4 beats for the harmony (i.e. half cadences), so when you get to m. 14, the second measure of a fifths sequence and also the harmonic rhythm shifts to 3 and 1, it makes the V/ii (D in the bass) sound like an afterthought resulting in a bVII to ii progression which is not as common. Far be it from me to tell you it's wrong, but I can help by explaining why it sounded off to me.