@LarsChristian 

Hi,
Thank you for the case report, and please refer to the tips below for a try.

1. On the Tapo app, click on the Tapo Cam and go to the Camera Settings>Advanced Settings>Display Settings, and then select the Compatible Mode and check if the problem solves.

2. If you use the Tapo app on a Huawei phone, please change the phone for a try. (For example, download the Tapo app on a different phone and then log in to the Tapo app with your TP-Link ID to watch and manage the cameras.)

3. If the problem remains, please help collect the following information.
1) What's the model number and OS of your phone?
2) What's the version of your Tapo app?
3) Just double-confirm: please try to watch other cameras on the same phone and then check if they work fine.

Best Regards