Hey people! I have a very odd problem. im on a cable uplink (& seperate DSL)where im booked into 120/5 (6/1 on DSL)  connection speed. Behind my Modem i have a Loadbalancing machine which balances connections for the two uplinks via shorewall, and i get a massive speed reduction when connecting through the switch the loadbalancer is connected to. The Loadbalancer is currently asked to route all connections through the cable provider, but the speed reduction when not beeing connected directly to the cable modem is mad. What could be the issue here?

Setup schematic:
https://docs.google.com/drawings/d/10OcA3U3GWQF2pqZKPbFe6BVWBDqDWWcagqPB-UecbCw/edit?usp=sharing

Speedtests:
https://www.dropbox.com/sh/w2z099j33q6yx87/AADBhbndAbfCV88X2NXflWLea?dl=0