Node 20 sends a broadcast message. Broadcast messages are received by all nodes, including node 22. Since node 22 is not a repeater, node 22 does not send a reply to node 20. That's just normal operation.
However, when node 22 sends a reply to the gateway's I_DISCOVER_REQUEST, the reply is not acknowledged (st=NACK). See https://forum.mysensors.org/topic/666/debug-faq-and-how-ask-for-help for a troubleshooting flowchart with the most common causes. Power is top 1, 2 and 3 on that list.
How is your node powered?
The debug logs from the gateway will probably be very useful for troubleshooting.