Have a look in the OPTIONS menu > Project Preferences.
There you can set the "Working Units" for the units and precision that you want to use when placing elements.
Also you will find "Dimensions..." which allows you to set the unit and precision you see in dimensions.
You can work in one unit and dimension in another that is completely different if you want to.
With the dimension units you can save them as a dimension scheme that you can choose in the Quick Options palette.
This way you can set up various schemes and quickly change between them.
The dimension schemes are saved with each view in the View Map so effectively you could have 2 or more views of the same floor plan showing different dimension units.
It sounds like you have accidentally chosen a different dimension scheme.
You also have "Calculation units & Rules" which is the units that your schedule will display.
All 3 preferences can be set to the same or different units.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11