@Cloud_Geek_82 Apologies for the delay in response and all the inconvenience caused because of the issue.
You can put External Load balancer behind RD gateway server so that load balancer public IP will be associated with A record instead of Rd gateway server IP .
From outside, if it is RD gateway public IP then it should work but if you don't want to expose the public IP of RD gateway (if you have) and want to do something else in BTE client and RD gateway, you can go for many options but all options are like load balancing options like load balancer (layer 4), application gateway (layer 7), traffic manager (dns), front door.
I have personally seen RD gateway and servers behind load balancer mostly.
You can indeed refer to this documentation which consist of details of process and might be helpful to you as well.
This documentation might be beneficial as well.
Hope it helps :) !!!
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