For anyone interested, I found the issue:
It was the timezone. I had forgotten to add the configuration for the GMT timezone to the SAP system.
Additionally, if you would like to debug any issues that don't show on the log, you need to debug class:
- /EHSMM01/CL_LWM_SAFETY_OBS_DPC
This class is called when submitting a Safety Observation. On the create safety observation method, there's a chunk of logic that checks for error message and then checks:
if error_msg is not initial then return;
So you don't really know what error message you're getting unless you debug the method.
Good luck!