Rude talking by my 8 year old

I have an 8 year old boy who is very rude to me in the way he speaks. Everyday things are hard to accomplish. If I ask him to clean his room he will say oh really? Why, why don’t you clean it?
He has called me names in the past even threatened to hurt me. I a little unsure of how to handle the situation. I do tell him he has earned an extra chore because the attitude & Blatant disrespect is a NO Answer and not allowed in our home. He still makes faces and continues to disrespect. He will do the chore but then continue making snarky comments to me later on after he is done. He has been caught Lying a lot. For example steals all the school packaged “goodies” he can find in the house even after I have repeatedly told him not to I find wrappers all over the house & will deny it even thought I know he did it. Today I got a email from the teacher saying that he was caught cheating on a test because he did not know the answer. He did not seem to care about this after I brought it to his attention and discusses it.
He seems unfazed by the consequences and then immediately does it again.
I’m confused at what to do as this seems like it’s a cycle of lies, meanness, disrespect and then doing it all over again. I feel like our relationship has gotten really sad over the last year because all I do is correct him it seems. His father is on board w/ THG but also has similar struggles. He does seem to break through better with him in several ways. I am stricter with him and hold him more accountable I think.

I’m not sure what to do at this point.
Thank you so much.