Value of width parameter changes after entering it


I am using LibreOffice Draw Portable on Win10.

I want to create a scientific poster. It is 90 cm wide. If I create a text box and enter a parameter in the “width” field, the parameter changes to a smaller number once I tab out of it. For example:
I enter 500 pt. It changes to 337 pt.
I enter 30 cm. It changes to 337 pt.

The text also becomes abnormally long, it’s height is off the page, while the greyed out height box says 46.5 pt. I can’t change that parameter or make the box shorter as the handles are outside the page.
I can manually drag the box to be wider, however the width parameter does not reflect that in numbers. I need precise box widths for a consistent 2 column layout on the poster. It is pretty frustrating to witness the software change values in front of your eyes to the wrong values.

On a side note: Is there a way to increase performance? The whole UI is sluggish and it takes 5 seconds between clicking on a text frame on an empty document and getting the draw handles to manipulate its size. I usually to High Def Video Edits on this machine, so there is enough VRAM, RAM and CPU available.

I’m happy for any help.

What is the Drawing scale value on OptionsLibreOffice DrawGeneral? (And btw, you didn’t tell LO version either.)