There seem to be duplicate events being sent to eventlircd.
You can see an additional KEY_RIGHT being sent after KEY_RIGHT_UP. Here is what I see when I do the same test. (On an OSMC remote on a Vero, but same principles apply)
osmc@vero:~$ irw
6a 0 KEY_RIGHT linux-input-layer
6a 1 KEY_RIGHT linux-input-layer
6a 2 KEY_RIGHT linux-input-layer
6a 0 KEY_RIGHT_UP linux-input-layer
69 0 KEY_LEFT linux-input-layer
69 1 KEY_LEFT linux-input-layer
69 2 KEY_LEFT linux-input-layer
69 0 KEY_LEFT_UP linux-input-layer
Notice there is only one key up event for both button presses. Can you try the following for me. Install a package called ir-keytable:
sudo apt-get update && sudo apt-get install ir-keytable
Then run the following command:
sudo ir-keytable
And post the output of this command here so we can see it. Then try running:
sudo ir-keytable -p lirc
Let us know if this eliminates the duplicate button presses. (It will only take effect until a reboot)