Measurement tool units not changing

Steps to reproduce:

• open Inkscape
• Change document properties: > File > Document Properties > Page > Units -- Change to mm
• Also (from same location): > Grids > Grid Units -- Change to mm
• Click Measurement tool icon and measure two arbitrary points.

What happened?

The result is always in px

What should have happened?

The result should be in mm

Inkscape Version and Operating System:

• Inkscape Version: 1.0beta2 (f3d5b5a, 2020-03-13)
• Operating System: Ms-Windows
• Operating System version: 10 64-bit