You have shown screen shots from TTN & your gateway so you definitely have more than the serial monitor! This means you have access to TTN so you can look at the console on the page for the device that you created.
The AppKey doesn’t care which way round it goes but it is simpler if it’s left as MSB.
Feel free to add screenshots but it’s harder to read on mobile devices - like now - so maybe I’ll wait until I’m back at a desktop in January!
I have no idea how a JR ends up with the mangled Dev & Join EUIs - I’ve used LMIC on & off for years so I’ve seen a fair amount of interesting issues but never this.
Maybe @kersing or @Jeff-UK can advise as they are gateway masters.