H-1B was approved with a new I-94 but the date of onboarding was extended by the employer
I was on H-4, and it was valid till Jan 2023. I got my h1b approved via the Change of Status application and it came along with a new I-94 date. My employer is saying that they need some time to onboard me. They are working on finding a suitable project for me and it is going to take some time. Is it ok to defer the joining date and should my employer or I file any application to let USCIS know that I am not starting the job right away?
That is not your problem, they should be really paying you. It is illegal. They cannot keep the employee out of a payroll. Employers cannot stop paying you merely because they don't have a project.