Chosen Solution
The fuel does not reach fuel filter. When you apply suction, fuel comes out of hose. Does this model have a fuel pump?
Completely common for a vacuum powered fuel pump on riding mowers. Follow the gas line from the tank and look for a square ~1.5” “sandwich” with 4 bolts and 3 hoses. Hoses are gas in & out and vacuum pulses coming from the crankcase. Disconnect the hose at the carb and crank the engine - no gas means pump diaphragm has failed.
