What zoom level have you selected in Lightroom? It should be 1:1
doesn't matter what zoom, it can be noticed in any zoom, the bigger the zoom, the bigger the cubes...but I know that this was not the problem before, only 2 days. I shoot lots of macro and I know it work well before, as my photos were perfectly clear
So are you saying that in response to my comment above, you have specifically checked the appearance at 1:1 zoom and the problem remains? It doesn't sound like you actually checked.
Show us a screenshot at 1:1 or 100% zoom and with the zoom level visible in the screenshot.
At 1:1 or 100% zoom each image pixel is one display pixel. The example image in your first post appears to be 3:1 or 300% zoom.
I would guess what is happening is your zoom slider is not visible so you're just toggling between Fit and whatever-else zoom level.
You can set the zoom level a couple different ways.
One is with the Navigator, either clicking 1:1 or for something else click the double-arrowhead and choose another level:
Or make the Zoom slider visible
You can also zoom in and out using Ctrl= and Ctr-: