Help needed. No notifications on new messages

[SR7673]

Hi IOS guys,
It's the first time i ever hold an apple device in my hand... My friens installed meshtastic on her IOS-phone and by default there is no tone when i write her a message.
The phone is connected to a RAK4631 with unsuspicious bahaviour when connected to an Addroid app.
The IOS meshtastic app is about 2 weeks old. And the phone is on IOS version 18.
In the phone settings there is nothing disabled which could explain the silence it seems.
I would expect that by default there is a ring tone when receiving a message.

So where does one have to look for the reason please?
Is this a known issue?

Regards...

[Carterdg]

I have Meshtastic App on my Android phone, no problem. I tried to install it on my wife's phone (iPhone using IOS 16.7.11) the App Store only has one for IOS 17.
How can I get an older version of the Meshtastic App for IOS 16?