H1B employment dates related question

[tikona2023]

Hi! I have a H1B employment dates related question.  I was employed by Company A (for their client G) on an F1 visa STEM-OPT which was valid until January 2023. My H1B visa was sponsored by Company B (for the same client G) and was selected in the H1B lottery in 2022. However, my change of status (COS) request was denied, and my H1B was approved with COS denial (code 1797B). Therefore, even in October 2022, I was still on an F1 visa working for Company A. Company A and Company B are sister companies.
In November 2022, I went to India for my H1B stamping. The day before my interview date, I received my 1797A notice (in response to the COS denial inquiry to USCIS by immigration lawyers) and got my H1B visa stamped on November 20th, 2022. I returned to the USA on December 1st, 2022, after a 20-day vacation in India. Company A paid me until the date of stamping, and Company B began running my paycheck from the time I entered the USA.

My question is, from an immigration perspective, was I employed by Company A or Company B between November 20th and December 1st, 2022?

Any information would be helpful. thank you!!

Edited March 18, 2023 by tikona2023
typo

[Zodiac System]

H1b work status applies when you are in US.  As you were in India I dont think H1b status applies.  Your employment started with company B from the time you came back to US.

[whiskeyjack]

You are employed by whoever pays you. That’s pretty much the case everywhere. Don’t go too much into technical details. CIS surely won’t.