Strange behavior (related calculations)

I have a huge problem that I try to solve last 2 days. I just can't se any the solution. Maybe is there a trivial solution but I can't se it.

I have 4 tables:

 

Overlands

Calculations

Income

Outcome

 

Overlands is the main Table, and it can have multiple calculations, and each calculation can have multiple incomes and outcomes.

The Calculation table has, for now, just 3 relevant fields. Cars, People, Earning.

The Income and outcome tables have bit more relevant fields.

1) "Price with Tax" (is calculation of fields Price & Tax)

2) Grand Total price is a calculation from fields "Price with Tax" (that can be "by car", "by people", or "fixed" amount) x number of Cars or People or 1 (when fixed), depending on the price attribute from the income or outcome table. Each table has o Summary field of " Grand total price"

The tables "Calculations" "Income" and "Outcome" are on the ovelrands Layout as portals.

What is the problem? If I set the number of cars or people in the Calculation table, the numbers in the Income and (or) outcome tables are sometimes updated, and sometime not. And that is the strange thing. It sometime works, sometimes not.

 

Any help is appreciated.

 

P.S.

Before entering Cars or People in the calculation, the "Select" button must be pressed to make the record active.

I cleaned up the file from not necessary tables, scripts and fields.