Hi. I'm using successfully the ir receiver, both directly, using ir-keytable package (without lirc), than installing lirc and creating remote configurations with irrecord (obviously I've connected a IR receiver to GPIOL11 and enabled IR in npi-config).
I'm sure about funcionality of lirc receiver because if I take a remote file generated on my Nano PI Neo Air and put in on another board where lirc trasmitter works, all programmed keys send correct sequences.
What I'm not able to do with my Nano PI Neo Air is transmit, with an infrared led connected to GPIO PIN 17, using lirc.
I'm also sure that lhe lircd daemon is running and the /var/run/lirc/lircd socket is available, but when I wrote, for example,
irsend SEND_ONCE MyRemote KEY_POWER
I always get the following two lines:
irsend: command failed: SEND_ONCE MyRemote KEY_POWER
irsend: hardware does not support sending

Some data from my installations:
O.S. is friendlycore xenial 4.14 image of 20191219 without any modification.
Lirc, installed with apt-get, is version 0.9.0 (this is quite old)
/etc/lirc/hardware.conf (to reamin short, I put only uncommented lines):
REMOTE="Custom"
REMOTE_MODULES=""
REMOTE_DRIVER=""
REMOTE_DEVICE=""
REMOTE_SOCKET=""
REMOTE_LIRCD_CONF=""
REMOTE_LIRCD_ARGS=""
TRANSMITTER="Custom"
TRANSMITTER_MODULES=""
TRANSMITTER_DRIVER="default"
TRANSMITTER_DEVICE="/dev/lirc0"
TRANSMITTER_SOCKET="/var/run/lirc/lircd"
TRANSMITTER_LIRCD_CONF=""
TRANSMITTER_LIRCD_ARGS=""
START_LIRCD="true"
START_LIRCMD="false"
LOAD_MODULES="true"
LIRCMD_CONF=""
FORCE_NONINTRACTIVE_RECONFIGURATION="false"

Would be great if someone could help me. Thanks