Occam's Razor is a heuristic, not a law. I think you're misunderstanding what it is. It doesn't mean aliens are impossible. It means the rational conclusion based on the evidence puts the probability of aliens very low. This is because, on the evidence we have right now, we know we are far more likely to be missing some quirk of science than to be finding aliens, because we have on multiple occasions found we've been missing out on science. We don't need aliens to explain this yet.

Show me a coherent information signal coming from this star and I'll change my tune in a heartbeat, but "the brightness of this star is behaving a bit oddly" just isn't that spectacular of a signal.