There are two reasons why knowledgeable people give conflicting advice at different times. One is political pressure, when mass murderers like Trump and DeSantis (and the UK's own bimbling incompetent Johnson and his government) push forward agendas that go against knowledge because their supporters will leave them if they don't. The second is that knowledge advances, like when it was originally thought that Covid, like most other coronaviruses, was primarily transmitted through surfaces and only later found to be primarily transmitted through the air. So listen to the latest advice from scientists in the field, not your friend on Facebook or Twitter. It may be different from last week, but that will be because new evidence has come in.