Is this normal after getting a job offer?

I am getting ready to start my second tech sales job making more than I was before. I already received an offer and the whole team reached out to me telling me how eager they are to meet me. But I have been having some hiccups with HR as they ran a background check on me and did not see two of my previous roles there (I did not lie). Then I send w-2s to confirm but they don’t say exactly the company name, they have the LLC on them so they gave me trouble about that. I even offered to hop on a call with them to help them clarify further but got no response after that. Job offer is signed and I’m getting my equipment in some days, but should I be worried? Is it normal to have this type of trouble after the job offer?

I really like the job and the people have been great before I’ve even started, I’d hate to lose it.