Thanks, but this does not appear to be the reason.
To test this, I changed my game display to 360 x 640 and repeated the same test by placing the tiles on the edges of the UI boundary as seen below:
As can be seen, the tiles are on the edges of 360 and 640 i.e. the display size of my game.
Leaving the camera settings at FIXED_ZOOM and ZOOM of 1, I get the following game window:
With this resolution, I have lots of space on my screen and it still comes out like this.
Would appreciate some help in understanding this .
With these changes, I expect the game to open and play in a 360x 640 window and see my objects placed exactly where I placed them in the editor, but that does not appear to be the case