Are managers expected to be available after work hours for their managers?

Hello I'm a new manager I manage a small team remotely and the work hours range from 7am to 3pm or 9am to 5pm.

We usually get things done before 5pm, and I'm able to finish every managerial duty around 5pm unless there's an emergency that requires me to stay late.

Sometimes my upper manager messages me on google chat at around 7pm to do something or check something, she never implies that it's time sensitive.

When I was a regular employee I simply muted the notifications, but as a manager I'm not sure what is expected of this position. She never complains or asks me why I didn't answer, but I'm worried that the norm is for us to be more available than other employees and I'm being the odd one out.