If I understand correctly you are trying to change an object that is not retrieved or found in your microflow. Be sure to check if the object exists.
Add $FinancialResult != empty in an exclusive split between the retrieve of FinancialResult and the change object activity. The true value will go to the change object, the false value somewhere else.
Not sure if you are still running into issues. What you can do is debug your microflow and see whats going on. I suspect the false path on your exclusive split is hitting, Meaning that the association you are trying to retrieve over is not being set correctly. To verify this you can set a breakpoint on the microflow and with the variables tab check to see if the financial result object is retrieved after your retrieve by association event (it will show up in the variables tab after the retrieve event, so you can put the break point on the exclusive split)
Here is documentation for debugging
If the object is empty after being retrieved, make sure the association is being set correctly to the parent object (in this case the object financial). If the association is being set correctly in another microflow, make sure you are committing the correct objects for the association to write to the database.
Here is the updated microflow:
Here is the change object: