I believe a Template Sensor’s state option is computed before its attributes option.
That means your state template attempts to reference an attribute that will only be computed after the state is computed. The state can’t be computed unless the attribute exists but it can’t be computed unless the state finishes its calculation. The deadlocked situation is reported as an error message in the Log.
Make the template for state refer to all theinput_number entities directly as opposed to via its attributes.
state: >
{{ states('input_number.diesel_tank_h') | float(1) *
states('input_number.diesel_tank_l') | float(1) *
states('input_number.diesel_tank_w') | float(1) }}