God can't lie and God can't change. Of course there's things God is not capable of doing.
That whole argument is a logical fallacy started by atheists in an attempt to try to disprove God. It makes them feel good to think they pulled a fast one over on Christians.
You really need to get a grip on your thinking if you've fallen for that one.
You didn’t answer the question: are you, in fact, suggesting that there is something that God is not capable of?