It would only be a problem if the USCIS has reason to believe that when you started the GC process you already had the intention of changing employers as soon as you got the GC because that would then be classed as immigration fraud. Since they would need some compelling evidence for that, this is a very unlikely scenario.I left my sponsoring employer 6 weeks after getting the GC.
Do you think it's going to be a problem during naturalization?