Not assigned to a project after entering US

Hi,
I am on H1B visa and have an approved I-140. I have some questions on my situation. I was working for CompanyA and I left US in April 2022 and went to India and my employer CompanyA relieved me in August 2022. Thereafter I transferred my H1B to another employer CompanyB in May 2023 while I was still out of country and did not work for CompanyB while in India and have I797B. Now I have entered US in January 2024 since my employer CompanyB had a project for me. But CompanyB has still not assigned me on a project and neither submmited I-9 form. In this situation what can I do, can I transfer H1B to another employer Company C without paystubs from CompanyB and that too while in US within 60 day period after I enter US? And what are my options ? Also a note my previous employer CompanyA H1 is valid until June 2024.

Thanks.

Are you not receiving salary after entering the US?

Not sure how they are showing you on payroll then. Ideally, your payroll should have been started.

Or have they started payroll and then stopped to get benefit of H1B 60 day grace period?

No, I have not been assigned to a project. My project was confirmed and I travelled based on that. So they haven’t filed my I-9 and not running payroll. So I need help, what can I do now ?