Motors Humming and not rotating usually means the “helping” phase for motor motion to start, is not doing its job. (what the capacitor is there for, it creates a phase shift to create a “second phase”)
Washing machines, being what they are, sometimes overloaded or vibrating can hammer the wiring either through heat (overload) or fatigue (vibration). As previously mentioned, the humming should always be checked, either a dead capacitor or dodgy wiring could be the issue, even if the drum and agitator do start running after a previous “dislodging” of something.