Zohar Parshas Vayishlach

There is a Machlokes Tanaim if  גיד הנשה is Muter or Asur  בהנאה (benefit)

 Reb Yehuda holds that it is Muter and Reb Shimon* holds it is Asur.

The Bais Yosef (Y.D. 65) holds that is best to refrain from having Hanaha from the Gid Hanasha because The Zohar (Parshas Vayishlach) writes that it is Asur Behanaha.

The Rema in Darkei Moshe writes, he heard that the author of the Zohar was R. Shimon (Bar Yochai) who is mentioned in the Talmud.

If that is the case, why care that the Zohar holds that it is Asur.

The Poskim rule, where there is a Machlokes between R. Shimon and

R. Yehuda the Halacha is like R. Yehuda.

It seems from the Bais Yosef that the Zohar was not written by

R. Shimon, otherwise How can you bring a proof that R.Shimon

in the Mishna Is right from the same R.Shimon (Zohar)

It is possible but unlikely**, to explain, the Bais Yosef means to say, to be

Machmir because Al Pi Kabballah (Zohar) it is Assur not only according

R.Shimon.

m*סתם ר' שמעון הוא רשב"י

**לא משמע כן בדרכי משה