The first thing you should address is the primary field in your Loads table. The primary field should be an identifier that is different from all other records, rather than just the date it was booked. You can use a formula field where you use string concatenation to create a Name field out of other fields. e.g.
{Date Booked}&" - "&{Origin and Destination}
I would do something similar for the primary field in the Operating Expenses table too.
Then, the key to what you are trying to do is the formula you are using for Load Month in the Loads table. You need to get that correct (there is trailing "r" for some reason), and then you need to use the same formula in a field in the Operating Expenses table.
Then in your CPM Calc table you should create a "First of the Month" Date field. Then change the primary field in the CPM Calc table to the same formula that you used in the Load Month table (changing the date it is calculated from to the "First of the Month" field you just created.
So now both your Loads and Expenses table have a Month field that is similar to the primary field in the CPM Calc. Now you can use an automation that triggers when a record is created in the synced CCC Loads table, use the Update Record action type. Update the created record by setting the CPM Calc field to be the Load Month field of the same record. That should do it. Make a similar automation for the synced Expenses table.
