No PPS pulse on RAK7246G

Issue: No PPS pulse on RAK7246G

Setup: RAK7246G running Raspberry Pi OS + Semtech basic station (latest versions)

Server: AWS

Details: base station software complains that PPS pulse isn’t seen and can’t synchronize clock.
Some of the LoRaWAN transmissions are ok, but most transmit packages are not send due to timing issue. The GPS works just fine (get every second a GSM packet on serial interface with correct coordinates).
PPS is set to ‘true’ in station.conf.
SPI enabled
I2C enabled
Serial interface enabled
Anything else to do besides ?