Problem after changing from GK420 to GX430


I'm really struggling for hours now to set up our new printer GX430T to replace our older one GK420D.

I have just installed the drivers and made sure setting on both printers are identical. (paper size, etc)

Below the correct one from the old printer on the left and on the right unreadable label from a brand new printer. (label format is epl)


Could anyone, please, help me to sort this out or even lead me how to find the solution?

Kind regards