LIRC Version 0.10.1-5.2 Linux Version 4.19.66-v7
New install today (apt-get update, apt-get upgrade)
apt-get install LIRC
(Basically repeating steps in https://stackoverflow.com/questions/57437261/setup-ir-remote-control-using-lirc-for-the-raspberry-pi-rpi)
edited /boot/config.txt and set:
dtoverlay=gpio-ir,gpio_pin=18
run mode2:
mode2 -d /dev/lirc0
space 4113301
pulse 1200
space 630283
pulse 1652
space 504625
pulse 1647
Good so far.
When I
sudo irrecord --device /dev/lirc0 --driver default
and enter the name for the config file, it continues with:
    Now start pressing buttons on your remote control.
    It is very important that you press many different buttons randomly
    and hold them down for approximately one second. Each button should
    generate at least one dot but never more than ten dots of output.
    Don't stop pressing buttons until two lines of dots (2x80) have
    been generated.
    Press RETURN now to start recording.
    ................................................................................
    Got gap (107126 us)}
    Please keep on pressing buttons like described above.
    Cannot find any gap, using an arbitrary 50 ms one. 
So it first reports it found a gap then didn't find a gap. It continues:
Please enter the name for the next button (press <ENTER> to finish recording)
KEY_1
Now hold down button "KEY_1".
Something went wrong: Cannot decode data
Please try again. (28 retries left)
Now hold down button "KEY_1".
Something went wrong: Cannot decode data
Please try again. (27 retries left)
Now hold down button "KEY_1".
Please enter the name for the next button (press <ENTER> to finish recording)
KEY_2
Now hold down button "KEY_2".
Please enter the name for the next button (press <ENTER> to finish recording)
Checking for toggle bit mask.
Please press an arbitrary button repeatedly as fast as possible.
Make sure you keep pressing the SAME button and that you DON'T HOLD
the button down!.
If you can't see any dots appear, wait a bit between button presses.
Press RETURN to continue.
....Cannot find any toggle mask.
Successfully written config file K5.lircd.conf
and if I view the conf:
begin remote
  name  K5
  bits            0
  flags CONST_LENGTH
  eps             0
  aeps            0
  one             0     0
  zero            0     0
  gap          50000
  toggle_bit_mask 0x0
  frequency    38000
      begin codes
          KEY_1                    0x0
          KEY_2                    0x0
      end codes
end remote
A well formatted output file with no values. I have used this same remote and the tool in earlier versions so have an idea what to expect. I also checked dmesg and there is no mention of a driver issue.
Any ideas what could be wrong. Many thanks
And in case you are considering updated hardware, I highly recommend the UART interfaced IR transceiver https://fr.aliexpress.com/item/32989940274.html. Using UART is a pleasure, comparing to IRrecord: https://raspberrypi.stackexchange.com/questions/103452/problem-with-lirc-on-raspberry-pi-3. – tlfong01 Sep 26 '19 at 13:47