H1b extension pay stub company name change

I work for company who has several offices in US. I moved from one branch office to another branch office under same job requirements ,profile and covers same territories. But the new branch office comes under different entity within the same company and has differerent EIN as well. I got 6 pay stubs with different company name on them. I am due for an extension in OCt 2020. Now Attorney is saying that this is a H1b violation and they have to file for new H1b under change of employer and I have to go back to India for stamping. Anyone faced similar kind of situation in the past. Not sure if there are any other options to make H1b extension smoother. Due to covid restrictions, it’s not easy to go to India and get visa stamped. Any help is appreciated. Thanks.