Posted by dellus on
URL: https://forum.librecad.org/Block-dimensions-change-in-library-tp5719564p5719570.html

Confirmed, you haven't missed anything.
I have discovered that when saving the block as a file for the library, the unit is mm, despite being cm in the original drawing. So it seems LibreCAD recalculates it to the units set in the drawing into which you insert the library part. If you open such a library file directly in LC and edit the Current Drawing Preferences from mm to cm all is fine again.