Reset due to error in src\ll_adv.c, line 974. Reason?

Question

Hi! I've been struggling with a bug on a nrf51822 product I'm working on. It features some I2C devices, a screen and a couple of sensors. The mcu gets a watchdog reset due to "src/ll_adv.c" on line 974 with error code 0 according to my app_error_handler() . I can't seem to figure out what might be causing the issue or how to solve it. 
 From my testing the error doesn't happen immediately, it can take anywhere from a minute to a couple of hours to occur. (Most common is ~15-30min) 
 I found this post from 8 years ago where there was a bug with the SDK and older HW versions. I tried setting sd_power_mode_set(NRF_POWER_MODE_CONSTLAT); but it did not solve the issue. 
 Setup: 
 
 OS: WSL Ubuntu 20.04 LTS 
 Soft device: SD110 V8.0 
 SDK: nRF5 V10.0 
 Chip: nRF51822 QFACA1 
 
 Where could I start digging to find the cause of the problem? What causes ll_adv.c to trigger the watchdog? 
 
 Best Regards 
 Isak

Isak A · Answer

Problem was incorrect usage of PPI settings, especially using CHEN instead CHENSET, CHENCLR should have been used. NRF_PPI->CHEN was used to set and clear individual bits when instead CHENSET and CHENCLR should have been used. The softdevice could put in a state which stoppped all radio communication due to this incorrect usage.