Up2stream WA31 Receiver security issue?

[Freeck]

I recently purchased a WA31 device. It does what it supposed to do very well.
I installed the 4stream app on my cellar phone and it also funtions as it is supposed to do.
But: when I am outside my private network or anybody else who installed the app via my local router, is still able to
control the WA31! This shouldn’t be possible, don’t you think so?

A second issue is that I am not able to update the firmware, if there is any? How is that done?

[Freeck]

Hello moderator,
Is the supplier Audiophonics not capable of answering my question? Or am I on the wrong forum?