Take a look at the Connection Server logs:
2021-09-24T22:05:34.737-07:00 ERROR (1B08-1A58) <SimpleDeamonThread> [h] (ajp:admin:Request190) Unexpected Origin: https://newname.net
The Unexpected Origin line will show you which portaHost entry is missing.
Also take a look at:
Cross-Origin Resource Sharing (CORS) with Horizon 8 and loadbalanced HTML5 access. (85801)
https://kb.vmware.com/s/article/85801
Unified Access Gateway(UAG):HTML Access fails with "Failed to connect to the Connection Server" (2151877)
https://kb.vmware.com/s/article/2151877
