Update after a long mail conversation with the support: None of their ideas worked either. Nor did any of the tutorials for bricked qualcomm chips because even with Qualcomm drivers the phone got recognized as input device and not as a Qualcomm device under Windows. The device information in linux mentioned Qualcomm as the manufacturer but it was still a input device.
In the end I returned my phone and they sent me a new one. A big Thank You! to the support at this point. I’d still be interested of the original phone could be repaired. With the new phone everything worked as it should to install OpenGApps and Xposed. Here my short instruction:
- update Fairphone OS
- install FP Open OS using the zip (in my case it needed to be transfered via PC)
- shutdown, boot into TWRP recovery which comes with the FP Open OS (Power, Vol Up)
- Install OpenGApps (full Tutorial here)
- and the XPosed Framework
- restart, setup your phone and disable location service to use the Playstore
- don’t format anything - retsifp was probably right.