Change of sum row in CAT2

Hey, SCN-ers!

I have made additional fields in the timesheet table of CAT2.

Now, I want my program to summarize values of these fields and display it in the respective field of sum row.

But, nothing is shown in this field.

I think, maybe it is blocked from changes? It's even difference in colors:

Are there any system settings for it? Or it's in the report?

Thank you,