Are we not allowed to talk?

I had a coworker this morning ask me a question. I stopped to talk to him for literally a minute and a half. The post master was staring at us the whole time and our supervisor came over to send me on my way. Are we not allowed to have a conversation now? I’m a city PTF and I’m constantly stressed that I’m going to get written up for some BS.

Coincidentally, we were talking about how we love delivering the mail but this place is stressful as hell otherwise lol.