@girish I came across this when I was doing some research on the issue.
"you can run your container in host mode and you will see the same networking that you see on the host, but there is no network isolation. When there is a bridge in between the packets from the container have to be natted and so one interface has to be chosen"
This explains why I didn't see the issue on my other systems since Guacamole is running in host mode there. I'll need to look at a different work around or create a seperate bridge and add the container to it.