Hello. Can you elaborate further on what you mean by "current pixel size"? Are you talking about the checker background? That has been changed in v0.7 to be unaffected by zooming, so it no longer has the size of one pixel. You can enable a grid in the View menu, "Show Grid" to help you with this!
The behavior of the transparent checkerboard was changed in v0.7 to be similar to other drawing apps. This way, jitter and dizzyness is reduced, which was especially noticeable in large images. Related GitHub issue: https://github.com/Orama-Interactive/Pixelorama/issues/208
You can enable the grid to help you with pixel-precision instead.