When sending data to a Splunk server for data collection, the proxy appears to be sending garbage data instead of log files.
The Access Logging Upload Client 'Save the log file as:' Transmission Parameters are configured to upload the log as a gzip file instead of a text file.
On the EdgeSWG SGAC console, go to Administration tab > Access Logging > Click on the affected Log file (e.g main) under Logs > Transmission Parameters
Select "Text File" beside the label "Save The Log File As:" and click Apply.