I was employed by employer A through their approved H1B. Their Form I-797 and its attached I-94 validity is printed as March 2021. In June 2019 I left voluntarily to work for employer B who have filed an H1B transfer petition and still pending. I started working for B on their receipt notice.
My previous employer A has not sent any revocation notice to USCIS.
Now I want to come back to employer A to a new project worksite which is in the same geographical area and same job description as their original LCA.
Q1. Does employer A need to file any petition? like I-129 Amendment or Change of Employer?
Q2. Is employer A’s original H1B approval still valid for me to simply resume working for them?
Q3. If for any reason Employer A’s approval gets revoked by USCIS (because I left them in June 2019) what will be my status? Does this impact my I-94 validity which is March 2021?
Q4. If employer B withdraw their pending petition, does it impact my status adversely?
Thanks in advance.