First I think it was a baddish cut of meat. Happens.
Second it may have been cooked too long for it's thickness.
My first experiences with steak/beef were wonderful. Seemed I couldn't go wrong.
Recently I bought a chuck roast, sliced it into chuck steaks, and had nothing but trouble.
Cooked one for 8 hours and was tough as an old boot. Cooked for 8 hours more and still chewy. 8 hours more and it was reasonable, but not by any means wonderful. It was still rarish, but dry. Not mushy but not juicy.
So I tried again and no better results.
The next one I pounded it mightily with a meat mallet and fried it in a pan. Was actually much better. Made a giant pot of stew with the rest which was excellent. Go figure.
Not saying buy expensive meat, because I don't and mostly it is superb. But it sounds like you got a less than optimal piece.
I have always preferred my steak blue rare when cooked conventionally, but for sous vide I find that 138 degrees is better. Taste and texture and juiciness. It is a different animal in a way.