Why does HP DeskJet 2620 add borders when printing 4x6 photos?

I have colour printer, Glossy 4*6 Inch paper and requirement where I need to give 2*2 inch photos

I decided to give it a go and print 6 2*2 inch photo’s on a one 4*6 inch glossy paper

What I did to produce image :

• created a project GIMP and opened the image
• select Crop tool and checked fixed Aspect ratio with 1:1 setting
• selected desired part of the image (Face area) and cropped
• opened cropped image in new frame ( by clicking on it)
• then created 6 tiles ( Filters -> Map -> Tile )
  • width x 3 and height x 2 ( here I have disabled aspect ratio)
• Set Print size ( Image -> Print Size 6 inch x 4 inch)
• export image

When I print the image it miraculously adds 0.5 inch margin on the left side, 0.1 on right and 0.3 inch on bottom and 0.1 inch on top as a result none of the tiles will be of 2*2

Center top tile will be close to it i.e. 2 inch width and 1.9 inch height

Not sure what I am doing wrong or where the problem is, any help appreciated to solve this mystery

Tried following Print options

• Default paper size : 4*6 as well as custom 102 * 152 mm with 0 mm
  printable area on all side
• selected scale to fit and Print Entire image
• Paper quality: Photo on Glossy paper – Fine

Printer: HP DeskJet 2620

Tool: Gimp 2.10

Original image ration (1:1) : 3000 x 3000 pixel

OS : MacOS Catalina