Same barcode printed in different UCC/EAN Modes?

We are trying to print a certain GS1-128 code as follows:

^BY2

^FO140,290

^BCN,110,N,N,Y,D

^FD421246001009011000006777617^FS

Our printer in the location A prints this perfectly and the result is scannable by a GS1 Analyzer.

However, our printer in the location B does not print a correct result because it is missing FNC1 characters that should be added automatically by the option D = UCC/EAN Mode. It doesn't. I had to change the FD to this:

^BY2

^FO140,290

^BCN,110,N,N,Y,N

^FD>;>842124600100>89011000006777617^FS

to get a GS1-128 scannable barcode, starting character set C and  manually adding the FNC1 characters.

The printer settings for location A are:

  10.0                DARKNESS         

  5 IPS               PRINT SPEED      

  +000                TEAR OFF         

  TEAR OFF            PRINT MODE       

  GAP/NOTCH           MEDIA TYPE       

  WEB                 SENSOR TYPE      

  MANUAL              SENSOR SELECT    

  799                 PRINT WIDTH      

  1214                LABEL LENGTH     

  39.0IN   989MM      MAXIMUM LENGTH   

  NOT CONNECTED       USB COMM.        

  NONE                PROTOCOL         

  <~>  7EH            CONTROL CHAR     

  <^>  5EH            COMMAND CHAR     

  <,>  2CH            DELIM. CHAR      

  ZPL II              ZPL MODE         

  NO MOTION           MEDIA POWER UP   

  FEED                HEAD CLOSE       

  DEFAULT             BACKFEED         

  +000                LABEL TOP        

  +0000               LEFT POSITION    

  NO                  HEXDUMP          

  043                 WEB S.           

  096                 MEDIA S.         

  008                 WEB GAIN         

  050                 MARK S.          

  050                 MARK GAIN        

  095                 MARK MED S.      

  009                 MARK MEDIA GAIN  

  095                 CONT MEDIA S.    

  007                 CONT MEDIA GAIN  

  066                 TAKE LABEL       

  CWF                 MODES ENABLED    

  ...                 MODES DISABLED   

  832 8/MM FULL       RESOLUTION       

  V61.17.17Z <-       FIRMWARE         

  1.3                 XML SCHEMA       

  V30.00.00           HARDWARE ID      

  CUSTOMIZED          CONFIGURATION    

  2104k............R: RAM              

  1536k............E: ONBOARD FLASH    

  NONE                FORMAT CONVERT   

  DISABLED            ZBI              

  2.1                 ZBI VERSION      

  28,405 IN           LAST CLEANED     

  28,405 IN           HEAD USAGE       

  28,405 IN           TOTAL USAGE      

  28,405 IN           RESET CNTR1      

  28,405 IN           RESET CNTR2      

  28J144202036        SERIAL NUMBER    

  MAINT. OFF          EARLY WARNING 

The printer settings for location B are:

  10.0                DARKNESS         

  5 IPS               PRINT SPEED      

  +000                TEAR OFF         

  TEAR OFF            PRINT MODE       

  GAP/NOTCH           MEDIA TYPE       

  WEB                 SENSOR TYPE      

  MANUAL              SENSOR SELECT    

  799                 PRINT WIDTH      

  1250                LABEL LENGTH     

  39.0IN   989MM      MAXIMUM LENGTH   

  CONNECTED           USB COMM.        

  BIDIRECTIONAL       PARALLEL COMM.   

  9600                BAUD             

  8 BITS              DATA BITS        

  NONE                PARITY           

  DTR & XON/XOFF      HOST HANDSHAKE   

  NONE                PROTOCOL         

  AUTO                SER COMM. MODE   

  <~>  7EH            CONTROL CHAR     

  <^>  5EH            COMMAND CHAR     

  <,>  2CH            DELIM. CHAR      

  ZPL II              ZPL MODE         

  NO MOTION           MEDIA POWER UP   

  FEED                HEAD CLOSE       

  DEFAULT             BACKFEED         

  +000                LABEL TOP        

  +0000               LEFT POSITION    

  NO                  HEXDUMP          

  042                 WEB S.           

  045                 MEDIA S.         

  008                 WEB GAIN         

  013                 MARK S.          

  021                 MARK GAIN        

  045                 MARK MED S.      

  032                 MARK MEDIA GAIN  

  095                 CONT MEDIA S.    

  007                 CONT MEDIA GAIN  

  066                 TAKE LABEL       

  CWF                 MODES ENABLED    

  ...                 MODES DISABLED   

  832 8/MM FULL       RESOLUTION       

  V61.17.17Z <-       FIRMWARE         

  1.3                 XML SCHEMA       

  V30.00.06           HARDWARE ID      

  CUSTOMIZED          CONFIGURATION    

  2104k............R: RAM              

  1536k............E: ONBOARD FLASH    

  NONE                FORMAT CONVERT   

  DISABLED            ZBI              

  2.1                 ZBI VERSION      

  8,070 IN            LAST CLEANED     

  8,070 IN            HEAD USAGE       

  8,070 IN            TOTAL USAGE      

  8,070 IN            RESET CNTR1      

  8,070 IN            RESET CNTR2      

  28J162703568        SERIAL NUMBER    

  MAINT. OFF          EARLY WARNING    

What causes the different treatment in UCC/EAN Mode?