If "Your Organisation is being consolidated, so all values are automatic and read-only" is displayed when you are looking at the values for the whole Organisation, Calxa is generating these figures as a sum of the Business Unit Budgets.
To edit the amounts, you will need to go to the relevant Business Unit and update there, then Calxa will re-calculate to report the full organisation amount.
If you are not sure which Business Units are used for an individual GL Account, you can view by the Account, and it will give you a list of the values for each business unit by month that make up the total amount.