RemoteApp Client tries RDP Gatway even if already connected to internal network with VPN

Hello,

i have a curious problem which i am not able to properly solve...we have some clients which are connected through vpn client connection or even vpn site to site connection

We have the following infrastructure

LoadBalancer (one VIP listening for port TCP/443, TCP/3389, UDP/3391)
VIP DNS Names = rdpbroker.local + +rdweb.local + rdpgw.de
-> rdpbroker address accessed by the Clients (rdpbroker.local) AND rdp Gateway address (rdpgw.local)

RDP Brokers (rdweb, Gateway and Broker installed)
rdpbroker01.local
rdpbroker02.local

RD Session Hosts
DNS Name = rdsh01.local
DNS Name = rdsh02.local
DNS Name = rdsh03.local
DNS Name = rdsh04.local

IP(!) is permitted for the Clients to all Systems, all Server Systems are in the same subnet (VIP included). This are the Settings for the collection

And this is a sample application rdp file

redirectclipboard:i:1
redirectprinters:i:1
redirectcomports:i:0
redirectsmartcards:i:0
devicestoredirect:s:*
drivestoredirect:s:C:
session bpp:i:32
prompt for credentials on client:i:1
span monitors:i:1
use multimon:i:1
remoteapplicationmode:i:1
server port:i:3389
allow font smoothing:i:1
promptcredentialonce:i:1
videoplaybackmode:i:1
audiocapturemode:i:1
gatewayusagemethod:i:2
gatewayprofileusagemethod:i:1
gatewaycredentialssource:i:0
full address:s:rdpbroker.local
alternate shell:s:||calc
remoteapplicationprogram:s:||calc
gatewayhostname:s:RDPGW.de
remoteapplicationname:s:Rechner
remoteapplicationcmdline:s:
workspace id:s:rdpbroker.local
use redirection server name:i:1
loadbalanceinfo:s:tsv://MS Terminal Services Plugin.1.FARM_Name
alternate full address:s:rdpbroker.local
signscope:s:Full Address,Alternate Full Address,Use Redirection Server Name,Server Port,GatewayHostname,GatewayUsageMethod,GatewayProfileUsageMethod,GatewayCredentialsSource,PromptCredentialOnce,Alternate Shell,RemoteApplicationProgram,RemoteApplicationMode,RemoteApplicationName,RemoteApplicationCmdLine,RedirectPrinters,RedirectCOMPorts,RedirectSmartCards,RedirectClipboard,DevicesToRedirect,DrivesToRedirect,LoadBalanceInfo
signature:s:

I tried Telnet on the ports, ping, mstsc on the address rdpbroker.local...everything works like expected but when i use the applications through radc they try to connect to the Gateway...but i dont know why?

Can someone explain why the Client doesnt recognise he is in the lan?

Any help is very welcomed

Thanks in advance

Kind regards