If there has been no configuration change because sometimes it works and sometimes it doesn't its important to check the following log file on the VDA 
C:\Windows\ServiceProfiles\NetworkService\AppData\Local\Citrix\Ngs

This shows if the connectivity is failing to CGS PoP due to which it is not able to establish a direct connection with endpoint 

in the log file you may see errors like 



TimeStamp=2026-07-14T07:07:21.282295Z ProcessID=5748 : {"Severity":"INFO","Method":"ngs-connector.(*Connector).parseNgsFqdnFromGct","Message":"[TECHSUPPORT] Successfully extracted NGS FQDN from GCT","TransactionID":"b446e652-5e12-482a-8104-3495ef4e85cd","FQDN":"reg.c.nssvc.net"}

TimeStamp=2026-07-14T07:07:21.282295Z ProcessID=5748 : {"Severity":"INFO","Method":"proxy.(*Proxy).DialContext","Message":"[TECHSUPPORT] Proxy is not configured or bypassed for connection","TransactionID":"b446e652-5e12-482a-8104-3495ef4e85cd","CustomerId":"XXXXXX","VdaUuid":"338ed3b5-50d8-a7d0-ed6a-070e9e6a2798","Address":"reg.c.nssvc.net:443","ResolvedAddress":"reg.c.nssvc.net:443"}

TimeStamp=2026-07-14T07:07:42.326975Z ProcessID=5748 : {"Severity":"ERROR","Method":"proxy.newConn","Message":"[TECHSUPPORT] [E304] Unable to connect to destination","TransactionID":"b446e652-5e12-482a-8104-3495ef4e85cd","CustomerId":"XXXXXX","VdaUuid":"338ed3b5-50d8-a7d0-ed6a-070e9e6a2798","Connection Type":"Internet","error":"dial tcp 20.105.71.129:443: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond."}

TimeStamp=2026-07-14T07:07:42.326975Z ProcessID=5748 : {"Severity":"ERROR","Method":"ngs-connector.(*Connector).doConnection","Message":"[TECHSUPPORT] [E100] Failed to register to gateway service","error":"dial tcp 20.105.71.129:443: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond."}

Random network connectivity issue

VDA machines must have access to certain URL as documented in 
https://docs.citrix.com/en-us/citrix-daas/hdx-transport/rendezvous-protocol/rendezvous-v2.html

VDAs that have exhibited succesful Rendezvous launch earlier may fallback to cloud connectors