I heard that some Chassidim (Bobeve, for example)don’t say “L’dovid Hashem Ori” beginning from Elul. I also heard that the reason for not saying “L’dovid Hashem Ori” is because there was a suspicion that this Minhag was introduced by the SHAT”Z (Shabsi Tzvi), as it is not mentioned in earlier literature, and is mentioned in “Seforim” of followers of the SHAT”Z.
Could someone shed some light on this?