Sound becomes very loud and distorted

Hi,
i'm using RR 3.7.2 64bit with a Gopro Hero 6 (PAL) and Motec data. When RR renders the mp4 file the sound becomes very loud and distorted.
https://youtu.be/NOII1S0UJdo?t=601 no data
https://youtu.be/2iI6Dzthsw8 with RR data

Any ideas?


OS Name: Microsoft Windows 10 Pro for Workstations
OS Version: 10.0.17763 N/A Build 17763

Processor(s): [01]: Intel64 Family 6 Model 85 Stepping 4 GenuineIntel ~2095 Mhz

Display adapter:NVIDIA Quadro P4000
Driver Version: 25.21.14.1917

Sound: Realtek High Definition Audio

Any ideas?

/Par