I was working fulltime(FT) on h-1b with company A & have transferred it from company A to Company B.Joined the new company B recently working FT for them.

1.Now Company A offered me to work parttime(PT) in the weekends along with my other job at company B. Can I legally work FT for company B and remote weekend PT work for company A at the same time? If so how many PT hours per week I can work with company A?

2. Should Company A file a PT H-1b for this remote weekend work? or the previous FT H-1b that I already had with company A before the transfer will still hold good? company A hasn't cancelled my old h-1b yet.

3. Can I do on and off on my PT job with company A while consistently working FT with company B? Legally should I notify company B about PT work at Company A?