RBS50 shown under "Connected Devices", but not under "Connected Satellites"

I have Orbi RBK50 in AP Mode with ethernet backhaul. I ran through all possible suggestions from this forum on how to get the enternet backhaul working properly (posts like this one https://community.netgear.com/t5/Orbi/Steps-to-reproduce-the-Orbi-backhaul-issues/m-p/1516065#M24646).

The Satellite RBS50 is connected, and it works fine over ethernet backhaul, but under connected devices on the Orbi Admin Page it isn't shown as a satellite, but as just another connected device. Why is that? 

My setup is: ISP Modem (in bridge mode) -> Router Asus RT-AC68U (with Merlin) -> Orbi (RBR50 & RBS50 in AP mode). Cableing is fine, I have tested each ethernet connection separately.

As far as I can tell, speed and roaming performance are both fine (500 Mbit over WLAN), it's just pissing me off that the satellite isn't recognized as a satellite, and I dont understand why. Do you guys have an idea what's going on?

See the picture attached, the satellite has the IP 192.168.1.61.