Weird experience

Has anyone ever experienced this? Someone messaged me and wanted to buy a Sunoo pc from me. I said sure and even sent them a video with flash of the pc so they can see the condition of it, etc. they then left me on seen and I gave them the benefit of the doubt, maybe they had to think about it first before fully committing which I completely get. Today I wanted to check in and ask if they’re still interested, just to see that they have me blocked?? What did I do? This is genuinely bizarre to me. 😭