2D sketching is not accurate. Please help

I’m sketching in the non beta version and everything is fine. I keep on drawing and following my measurements. Suddenly after a while I start seeing a bunch of decimals on something that should have been for example- 150.00 mm
I start zooming in at the circle isn’t matching up with the grid, it should be perfectly on the thicker line of the grid.
It’s not, I measure with a normal straight line and it’s 0.003 mm off, wish I could show a picture but apparently I can’t since I’m a “new user”.
I made sure the circle is centred so yeah, I Dont know what to do but I’m sure there is something
All help appreciated

The visual glitch is just due to how curves visualized, it’s because of tessellation. In reality the underlying curve’s representation is accurate.

To measure something, use the measure tool or create a drawing.