Number of decimals in measure

I made a drawing.
Lateron I changed in the menu the number of decimals, but in my sketch the number of decimals keep with the false number of decimals.

Is the normal. If not, how can i solve my problem?

You probably changed the precision in Current Drawing Preferences => Units.
This changed the precision of the coordinates widget on the bottom left.

When you want to change the precision of dimensions in the drawing, go to Current Drawing Preferences => Dimensions.
There you can set it.

See https://librecad.readthedocs.io/en/latest/ref/draw-prefs.html?highlight=precision#dimensions

LordOfBikes thanks for your clear explanation.