2048px square texture blurr problem

I created 2048px square texture but I have blurr problem.

1024px square texture have clean edge so I think this problem cause unity shader or texture.

Only 2048px squate texture has this blurr.

I reserched texture blurr in web and tried fixed problem but I have'nt got clean edge in 2048 texture square.

this is three list of fixed.

1,off the Generate Mip Maps

2,Filter Mode is Trillinear

3,Format is RGBA32bit

If you have advice,please let me know.