It seems, that you have activated Vertical Restriction mode.
See this post:
http://forum.librecad.org/how-to-calculate-a-surface-tp5716879p5716882.htmlIt is about Horizontal Restriction, but the Vertical Restriction button is right beside it.
The coordinates are shown in units. Means when you have set Inch in drawing preferences, it is 24 Inch.
You have to zoom in more, then you will get a grid that is 1/16th (the dots) and full inches are marked as continuous doted lines.
Grid is dynamically in LibreCAD, it depends on the zoom level.
Armin
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