Sophos SSL VPN - Severe performance issue after upgrade to XGS-2100 SFOS 19.5.3

We previously have XG-210, SFOS 19.5.2 but due to EOL on XG-210, we are forced to upgrade to XGS-2100.

We are now running the latest SFOS 19.5.3 on the new XGS-2100, and all SSL VPN users are experiencing severe performance issue.

The issue is impacting "All Users" in the business and affecting productivity for the past month with no resolution.

I have logged the case to Sophos Support and a lot of follow up but the issue is still pending with NO Action Plan despite me repeatedly requesting for immediate assistance.

Any one else is having the same issue? 

SSL-VPN Current Setting

Tunnel access: Use as default Gateway (Currently turned off but turned it on for testing, same issue)

UDP | AES-128-CBC | SHA2 256 | 1024 | Compress SSL VPN (Disabled, previously turned on) | Enabled Debug Mode (Disabled, previously turned on)

Support has requested logs and logs but no action plan. 

Edited TAGs
[edited by: emmosophos at 5:04 PM (GMT -7) on 16 Oct 2023]