After receiving GC, can employer still withdraw / cancel GC petition (I-140 / I-485)?

[us-im-1]

Hello all, I recently (few days ago) received my Green card (EB-1c). I wanted to ask you all a quick question.

Once we have GC in hand, is it still possible for employer to withdraw the petition (I-140 or I-485)? If yes, what is that period (few months or 1year etc.?)
E.g. within 6months or 1 year of I-485 approval or GC receipt - employer can still withdraw or cancel I-140 or I-485.

Reason I am asking this is because, I want to start taking interviews with other employers and shall quit my current employer if something good comes along. So please help.

Thanks so much for your help!!

[Enub4]

From what I read on forums, your employer can not withdraw your application because it is already approved. At that point, you can quit or work in another job.

Some say it "looks bad" if you change employer in less than 6 months but I don't know if it will cause any issues with GC renewal or Citizenship. I mean, if you get a better-paying job, any normal person will take it.