Very large tilemap disappears until camera at top/bottom edge of tilemap

Hi there,

I am building a game with TGB that uses a tilemap to represent a side view of a building, and this building area is the main gameplay element that other animated sprites are then placed on. This is working and working well for many levels, but I have run into a problem when building a level with a very large building.

My tilemaps use tiles that are 256 x 256 in size and the level I am having trouble with has a y count of 20, which makes the total height of the tilemap 5120. This is the largest tilemap in the game so far.

What happens is that the tilemap does not display in game, unless the camera is panned all the way to the upper limit or lower limit of the tilemap, and then it suddenly appears. My guess is that it might have something to do with the clipping of the tilemap?

I also notice that when using the level editor of TGB, that the only way to get the tilemap to appear is to zoom out far enough so that the tilemap does not get clipped by the editor window.

My question is does anyone have a specific idea about exactly what is going on and if there is a workaround for me?