Did you (try to) configure it for only TTN? What does the “Servers” page in your screenshot show?
Though maybe the verbose logging in your screenshot might be incorrect when it’s trying to interpret packets for which the CRC clearly failed (or for LoRa traffic that is not LoRaWAN traffic), a Join Request followed by a Join Accept after 5 seconds nicely fits the expected RX1-timing, so seems to indicate it’s communicating to some server?
But the DevAddr in that Join Accept, and the ones in the downlinks, are not TTN addresses (which should start with 0x26 or 0x27). And assuming this is running as a gateway (right?) then it should not hear downlinks transmitted by other gateways. So, seeing logging of downlinks with non-TTN addresses doesn’t feel right to me.
Unless you know what you’re doing, you should only connect your gateway to a single network.