Testing a Citrix XenApp application using Burp

I’m attempting to test a Citrix XenApp application by running it on a Windows 10 VM (VirtualBox) guest machine, and proxying the traffic through a Burp Professional proxy on the host only network (the proxy sits on the bare-metal host).

If I connect in this manner, the windows hosts starts making a bunch of requests like

 HEAD / HTTP/1.1
 Host: yuhakmeovo
 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.72 Safari/537.36 Edg/90.0.818.42
 Accept-Encoding: gzip, deflate
 Connection: close

where the host is any arbitrary 10 character domain. When the proxy doesn’t respond to these requests, (or responds improperly. This is a bit outside my ken), Citrix determines that the host isn’t connected, and stops until I bypass the Burp Proxy. This is, unfortunately, a major problem for intercepting traffic and actually testing the application. Is there a common solution?

If I get past this hurdle, I may still stumble on the certificate, (https://forum.portswigger.net/thread/interception-of-citrix-netscaler-traffic-66b481ce. ) but I’m not even out of the gate yet.