Mine shows 10Gbps but the speed is down 2.5Gbps / up 4Gbps. I think this is very much a bug from the latest merlin firmware. I didn't encounter this before when using asus official one.
I’m facing the same problem as well. Exact same version.
Guessing whether the beta version would solve our issue. Currently there’re 2 of them on sourceforge for 102.6.