Just for the sake of completeness:
Note that a DevAddr is not unique (like for the EU-region TTN only uses at most 4,096 different values for all ABP devices). Also, a DevAddr will change for each OTAA Join. (Though a device should not need to re-join very often, if ever.)
You’re seeing an OTAA Join Request, which apparently either is not handled by TTN as the device is not registered to TTN, or for which TTN has commanded another TTN gateway to send the Join Accept (if the request was received by multiple gateways). The DevAddr is only assigned after the join request is accepted by a network, so at this point TTN Console cannot show any network details. You will see the DevAddr for data uplinks.
If the device happens to use a TTN-assigned AppEUI, then it starts with 0x70B3D57ED. But a device can also use its own AppEUI when registering on TTN.