Why did the cabin crew disappear?

I have a question and something has been bothering me, which is why my fear of flying has gotten much worse. I was once on a flight in Mexico, a short/medium-haul flight, and shortly after takeoff, the entire cabin crew went into the cockpit with the pilots and didn’t come out for 45 minutes. I even pressed the call button for the cabin crew, but no one came. What was going on? I was terrified, and since then my fear of flying has become much worse. Maybe someone here knows and can tell me why this happened.

Thank you already and you all have a safe flight!