This is known behaviour of the NSX-T Data Center Load Balancer.
Workaround:
To use HTTP/v1.1 for communication to the pool members, enable TCP Multiplexing on Server Pools Additional Properties:
- Login to NSX UIĀ
- Click Networking tab
- Under Network Services, Click Load Balancing
- Click Server Pools tab
- Scroll to the target Server Pool
- Click on theĀ ellipsis beside it and click edit
- Expand Additional Properties
- Enable TCP Multiplexing
- Click Save