The Shenzhen-only five-day visa has never been available at Shenzhen Bay, the only land crossing now open with Shenzhen.
Thanks. Do you know about the Zhuhai SEZ visa at Gongbei (which is open)?
I assume you know that if you did return to HK from Shenzhen (or Zhuhai) there'd be a two-week home quarantine.
Yes, I specifically mentioned being aware of this in my post, to try to keep the thread on-topic.