Problem printing correct size labels on thermal printer

[Sayan25028646xt4x]

Hello,

I have an issue with printing shipping labels on the thermal DYMO 4XL  printer. The PDF file provided could be printed out on a laser HP printer, it also could be printed on DYMO 4XL printer but in incorrect paper size, however, when changing the printing label to the correct 4 x 6 size, the printer prints out black pages and then the sign comes up: "The document could be printed", and after I click OK, on another sign comes up "An error occurred while printing the document"  Please see attached screenshots. 

I was able to print out the shipping labels in the correct 4x6 size before without any issues, but something has changed. 

Does anyone know how to fix the issue?