So you create a new topic for the problem, and then go ahead and reply on your old one? logic sense makes.
is useless, the camera will be automatically set to a value, you don't need to set the zoom every frame when its not changing, you only need to change the zoom when it is actually changing.
Your map may be too big for your screen, so you need to move the camera around the world to see it all.
try changing the values in
this can also have a effect (i think, changed some values for mine in a sample i was playing around with to learn LibGDX)