XG 310 to XGS 3100 migration issue

Question

I recently moved from XG 310 to XGS 3100 but when i route their Internet traffic through the XGS, it greatly slows down. 
 I had the same issue when I upgraded the firmware from 19.5 to 20.0 but after doing a downgrade, the issue was resolved. 
 However, the XGS doesn't support 19.5. And I am still facing that challenge up to now. 
 How can I resolve that issue on my new XGS 3100. 
 
 Note: The same configurations that were on the XG 310 were migrated to the XGS 3100 Successfully and the XGS is on firmware version 21.0 MR3

Mayur Makvana · Answer

Hello, 
 You may refer to the below KBA for troubleshooting 
 https://support.sophos.com/support/s/article/KBA-000006849?language=en_US 
 Sophos Firewall: Troubleshooting network and connectivity issues 
 If you still have issue, we suggest raising the support ticket with your observation. 
 https://docs.sophos.com/support/help/en-us/portal/userGuide/cases/caseCreateTechnical/index.html