Indoor 2K HomeKit doesn’t work when absent

Hi folks,
I have the indoor 2K camera integrated in HomeKit. When every one is absent, my wife can check the camera on her iPhone, also my iPad gets notifications.
On my phone however, that doesn’t work when being on mobile Network. Being on a wifi (outside home) I get the notifications as well and can see the camera working.
Is there any setting which is related to this? I checked everything I could think off so far.

Automation in HomeKit was too complicated, the it never worked as I intended to, so ignored it and went back to eufy app to set things up.

Automation does work fine, even a switch is set correctly. On my work IPhone and the Iphone of my wife the streaming works fine also outside the home wifi. Switching other stuff also works from my phone.