Question: My maple document gives wrong units

Hello everyone!
I have had an issue for the past weeks, where it seems like Maple has a problem identifying the correct units and also sometimes having an issue with defining a variable.

In the picture below you can see I have defined rho, m and tried to Solve V. I get m^3, which is fine but I cannot change the unit in the right bar (see picture).

I even tried to just take square root of my V to see if I could then change units. It seems like it thinks I'm playing with weight.
I even had 2 teachers trying to help me find a solution, without luck.

I have tried executing the whole document and also only bits of the document without luck.

Does anyone know this problem and has a solution?

Thanks in advance! 

- Jacob