Hi schroepfer,
That’s interesting 
I am assuming you download the Seeed nRF library from Arduino IDE directly. Maybe you could try uninstall all seeed nRF libraries in Arduino IDE, then download the seeed nRF52 board library directly from github.
Go to the github page: GitHub - maxgerhardt/framework-arduinoadafruitnrf52-seeed: PIO repackage of the Seeed "1.0.0" core (Adafruit nRF52 core fork)
And follow the instruction how to download the repository directly from git.
Regards,
John