Getting Error 1020 on all BitcoinSV blockbook explorer instances. Why is this happening?

No I do not have control over those domains. They’re operated by different companies in the blockchain space. Guarda, atomicwallet, nownodes respectively.

They all exhibit the 1020 error. I suppose it’s possible they all banned access but that seems unlikely to me. Especially considering I haven’t really used at least one of them nownodes, so why would they even institute a ban?

An analogy would be like troubleshooting piece of PC hardware, you think there’s something wrong with GPU but then you go ahead and try 3 other video cards and they fail to POST with a display. Is it possible all 3 cards are bork? Sure. But is it likely? Probably not.