Load a new Draw document.
In the Draw options set the drawing scale to 1:50 and units to millimeter.
Draw a horizontal dimension line wider than 1000 mm.
Get the size and position dialog of the dimension line and reduce the width to 500 millimeter.
The dimension line displays 500 mm but when you call the size and position dialog, the width shows a much higher value near 2000 mm.
I cannot reproduce this error given the information provided.
I am using Version: 126.96.36.199 (x64) on Windows 10 [Version 10.0.19042.928]
After resizing the line using the property dialog, the line width value changes. When I click off the line, then reselect it to show the property dialog, the width is still depicted as 500mm.
But I am not the only one: https://forum.openoffice.org/en/forum/viewtopic.php?f=11&t=104915
[Automated Action] NeedInfo-To-Unconfirmed