Infinity down scrolling background

How to make vertical infinity scrolling background? Im tried with infinity scrolling background sample, change X to Y and other values.it works upwards.but when i try to do it downward it dosen’t work.i spent many hours and still can’t figure it.

I also tried with tiled sprite and offset Y method.it work.but few minutes later background getting blurry and laggy.

Is there anyway to make infinity and vertically scrolling background possible? I need it downward not upward ( im making space shooting game)

I would create my spaceship with TopDown Behavior, and create random enemies on top (out of screen) assingning platformer behavior.

I already have custom movements and enemy spawning system.so i think that dosen’t help. (Sorry about my bad English)