According to the documentation, I have created a few cost types in the admin section of my installation. I also have enabled the Budget module in the project settings. When creating a budget for one of my projects in the budget creation view in the planned unit cost section I am only able to view UNITS, UNIT NAME, COST TYPE and the COMMENT, but I am missing the BUDGET. If I complete the creation of budget, I am not able to log unit cost or even log time in the project to a work package. What I can do is successfully select a budget for the work package. In another project I created I did the same thing and I can add a budget in the creation view of a new budget. And as well, select the same cost type as units when I want to log them to a work package. 
What am I missing, why is it working in one project and not in another? I am in both projects, project admin.
I could not find any information that helped me any further, and as far I couldn't find any option in the documentation that would help me to solve this.

Is this the right place to ask?
Thanks in advance.