Is this home buyer scamming me?

My house is posted for sale on several different social media sites. Recently a person reached out from the letgo app and after talking back and forth for a bit, they had a cash offer. They claimed to be a house flipper. They haven’t seen my house other than online photos. I do have a realtor, which I explained to them, but they’re speaking with me directly. Obviously they’d need to go through a realtor to do this properly I assume. Is this just a scam? I’m very leery of this cash offer for lots of reasons but I just don’t see what they’d be gaining out of it. I tried telling my realtor about the situation but haven’t been able to get a hold of her yet. Thoughts?