if it did not click it might be the stand switch, the clutch switch, the starter button
if it clicks it might be the starter relay , wires, starter solenoid, starter, battery or battery wires/connections and i suppose it could be ign switch not allowing enough current to flow through the starter relay.
in this particular case guessing is not working very well. i think the only way is checking with a volt meter.
and u have to check when u are experiencing the problem. you have already checked when working and know what the volts when working
u have two areas to check
1 at the starter relay at the wire going to the starter solenoid
and at the starter post where the wire goes into the starter.
one test you might do is at the starter relay is the to remove the ignition power and install battery power wire.