Hello and thank you for taking the time to read.

I'm a Canadian currently working in a machine shop in Japan, with Swiss style machines. I run 6 different machines daily, 4 of which are Citizen L20s (2x 5M7, 7M8, 3M7), one Citizen B12 and a Tsugami B0205. I've noticed some machines have more restrictions than others. In this case, the GOTO command. One of my L20s(Named #69) can recognize GOTO commands, and the other(#18) cannot. It's not a huge deal on the L20s, as our company's programs and the parts we make are quite simple, I just have a little less freedom programming on #18 than #69.

On the Citizen L20s, there is an softkey you can press during the machining process called 'haraidashi.' I'm not sure what it's called in English, but when activated, it will re-run the back chuck machining process on the last part (typically a 120° drill used for caulking or a taping cycle). If you have experience on Swiss style lathes, I'm sure you know what I'm talking about.

Anyways, the Citizen B12 does not have this option, and I was planning to program it in by using the counter's macro(system variable) and an IF statement followed by a GOTO command to run the caulking once more on the last part. For example:

IF[#3901GE[#3902-1.]]GOTO64

GOTO65

N64
M98P6464

N65
yadayada

O6464 of course being the subprogram to rerun the back center drill which Z value I would also macro in

Anyways, this came up with an 'invalid address' alarm. To test the problem, I made a simple GOTO test program in MDI mode. The machine came up with the same error right on the GOTO command. Macros themselves seem to work, however. For example if I was to say:
#511=300.
M3S#511

The main spindle would rotate as expected at 300rpm. It's just the GOTO command that isn't registering. So my questions are,

Why will some machines accept GOTO commands, and some won't?
Is the any way around this, or any way to enable GOTO commands? I read somewhere the you need to change some parameters to make them work, but I'm not super keen on messing with something I don't understand fully.

Thank you in advance for taking the time to read.
-Andrew