The reason for that is that mobile devices do not allow their native cameras to listen to the parameters that are sent to them.
The way to make it work would be by using the WebRTC instead.
For this you should turn on the WebRTC for mobile option, however since Safari has a bit different implementation of WebRTC you would also need to add WebRTC if necessary option to follow up.
You can see more how to set these up here: https://github.com/Ziggeo/vue-ziggeo/#recorder-application-settings
For example they would look like so:
As you add these, you will notice that the native app is no longer opening.
Please do try it out and let us know how it goes.