Feed per rev is G99 under Mach4 and is set.
This is a link to a YouTube video of the issue
https://youtu.be/YqWxuqiohYkThe Gcode is correct to the manual, and also the built in screwcutting wizard as listed below.
N0 (Machine type - MachMotion Lathe Canned Cycles)
N5 (Filename: C:\Mach4Hobby\GcodeFiles\fffg.tap)
N10 (Generated on 03/27/20 at 13:38:32)
N15 G00 G40 G54 G64 G80 G90.1 G99 G18 G21 (Safe Start Block)
N20 %
N25 %
N30 (Starting Gcode for Threading Cycle: ThreadingCycle-0)
N40 G00 G40 G54 G64 G80 G90.1 G99 G18 G21 (Safe Start Block)
N45 %
N50 %
N55 T0101 (Tool Change)
N60 G99 (Feed per Revolution)
N65 G97 S400 (Constant Speed)
N70 M03 (Spindle Forward)
N75 M09
N80 G00 X14.00 Z5.00 (Rapid move to Clearance Height)
N85 G76 P020560 Q0.05 R0.3 K1
N90 G76 X9.72 Z-20.0 R0.0 P1.14 Q0.3 F1.5
N95 G80
N100 (End Gcode for Threading Cycle: ThreadingCycle-0)
N105 %
N110 M09
N115 M05
N120 M30
N125 %
N130 (End Gcode file)
N135 %