Notifications not working on iPhone, unless also send to iPad

Hi,

I’m new to Home Assistant and still exploring everything.
I wanted to experiment with notifications, but no matter what I tried, they didn’t arrive on my iPhone.
The trouble shooting guide also did not provide a solution.
Then I came up with the idea of ​​installing the app on my iPad and the notifications did arrive there…
When I now send the notifications to both devices, they also arrive on my iPhone. When i remove the iPad from te notification, they are not received on the iPhone anymore.
Is this a bug?

Regards,
Gunther.

iPhone: 17.5.1
iPad: 17.5.1
HA: 2024.7.2