Connecting Edge 1050 to Android via USB

Tried to connect an Edge 1050 to my Android Smartphone via USB-cable. The idea was to transfer files from/to the device.

This works fine when connecting the Edge to a Windows computer, but connecting to an Android Smartphone never worked.

I tried different cables (regular USB-C, USB-OTG), but filetransfer was never possible.

Smartphone is a Google Pixel 7 with newest Android-version.

The phone recognizes the 1050, but all options for filetransfer are grey, and it is not possible to switch control to the phone.

The 1050 supports the MTP-filetransfer-protocol, Android also supports MTP: why is filetransfer not working?