360 spherical panoramas retouched areas are blur

I use this workflow for retouching 360 spherical panoramas in Photoshop cc Version 21.2.3

1. I open an equirectangular 360 spherical image (5000 x 2000 Pixel)
2. I convert it with 3D > New Panorama Layer from Selected Layers
   (After this step, when I zoom in in the 3D layer to 100% I can see that the Panorama is blurred.)
3. I insert a new empty layer
4. In this empty layer I retouch the image with clone tool
5. I merge the empty layer with the 3D layer (STRG+E)
6. I export the new Panorama

The problem is that the retouched areas are blur, very blur! Only the retouched areas, the rest of the 360 image is sharp. 

The extra layer is only for non-destructive work while cloning. Even when cloning directly in the 3D layer, the retouched area will be blured. 

Is this a bug, or is there something that I missing?

Can someone who also use the PS function 3D > Panorama... tell me whether he finds the same problem?

Thank you.