From one day to the next, a whole group of people goes weird. But no one says anything. Are we just imagining things? Maybe we did something wrong? So how can we decode this? In this case, a listener is experiencing this in a work environment.

A few things stand out: how can we tell if we're the problem? Usually, being worried we might be is a rather safe indication we are not.

Then, if we can't think of an event that triggered it, it reduces the likelihood there was such an event.

If people are weird around us, we can sometimes identify who is uncomfortable at being gossiped to, and simply ask if they'd let us know if something got weird.

And remember that this could be a form of mobbing, which might require to involve HR, or management.

Consider options to discuss, but also options to leave in case it is unhealthy and there is little or no support.

As always, exercise your judgement and adapt to your situation.

Hope this is helpful and let me know if you have other questions where my take could be useful in providing elements to decode situations.