Issue with FirstConfiguration sketch sending messages and always getting time out error code (-1)

I am having issues with sending messages from my MKR WAN 1310 to TTN (now The Things Stack Community Editon). I have an indoor gateway which works and sends messages to TTN. However I can not get the MKR WAN to send messages. My MKR WAN is using the Europe 863-870 MHz band, has a "official" X000016 Antenna, and is brand new. I updated the firmware using MKRWANFWUpdate_standalone (I am using the MKRWAN_v2 library for everything). Then, I ran the FirstConfiguration sketch, follow the guide on Arduino's documentation. I get my APP EUI and APP KEY, send it through serial, and the arduino conects. Then it tries sending a message and then fails with the error Error sending message :(. I have tried many times, with breaks (to avoid rate limiting) and this happens every time.

Any help would appreciated!

Please provide clickable links to as many of the things you have mentioned, as is possible. Post any error messages in their entirety, in a new post. Especially that. I suppose it's a serial diagnostic messsage? Post the whole message.

Because you are actually running reference code, you might have a hardware issue so you should provide some details that might reveal any wiring, configuration errors...

As requested, here are the error messages I get while running First Configuration:

I will put the enitre Serial Log (without the keys of course) here (it is short):

Welcome to MKRWAN1300/1310 first configuration sketch
Register to your favourite LoRa network and we are ready to go!
Your module version is: 1.3.0.0
Your device EUI is: BLURRED
Are you connecting via OTAA (1) or ABP (2)?
1
Enter your APP EUI
<I enter my APP EUI>
Enter your APP KEY
<I enter my APP KEY>
Error sending message :(

Hardware Information:
I have a brand new MKRWAN 1310, connected via micro usb to a Mac Mini. It has additionally a Arduino X000016 Antenna, but nothing else attached to it.

TTN Device Panel

How far away is the node from the indoor Gateway ?

1 meter :smile:

Stupid question, but can it be that it is too close?
I checked the coverage map - there are basically no gateways except mine in the area

Move a lot further away, say 10M and several walls in the way.

Got it. I was going to test, and then in "production" I would move it further away. I did not know that it was important - thanks

Yes, the node can be too close, the Gateway can receive on several channels at once and it gets real confused.

I will keep the thread open while I try this again, but thanks!

I still get the same error, even though I have moved 10M and a few walls away. I will try again, to see if this was just a fluke

It is one thing to check, and is known to cause problems when testing some setups.

That screen shot appears to show the node joining, processing and forwarding messages ?

Yes, I saw that too, but the sketch always shows the same error

"However I can not get the MKR WAN to send messages"

Looks like it is sending messages ?

Sorry, I misworded it, its just the sketch always complains

I changed the post name to reflect my new issue

Strange, I checked the payload logs - sometimes the payload is 48654C6F524120776F726C6421 (HeLoRa world!) sometimes its 00 - but the sketch always complains. Maybe there is some data loss?