I am testing an end-device at the moment which is only able to reach the gateway when using SF12 (due to the distance and obstacles between them). Due to the TTN characteristics the corresponding downlink is not sent using SF12 as well as the uplink but instead is sent in the RX2 Window using SF9 and TX Power 27. This setting is correctly transmitted to the gateway (tcpdump shows powe: 27 for the received downlink) but the end-device is not able to receive the downlinks.
Regarding the setup:
I use a Kerlink gateway and a Feather board as end-device.
There are some other similar posts in this forum but non of them really helped me solve the problem.
Do I need to configure the end-device in a specific way to be able to receive the downlinks?
Or must I configure the gateway to make sure that the TX power is actually changed to 27?
Or is there another way to solve this problem?
I’m looking forward to any kinds of hints.