Yes, you shouldn't need to jump the solenoid normally, I guess you know it's an inconvenient way for starting but is necessary sometimes if there's a problem.
So what happens if you try to start by using the start button as intended, does the solenoid make a click sound but the starter doesn't receive any electrical juice? If yes, probably the internal contacts are corroded.
I replace many solenoids for customers with this problem and I save the old solenoid if they don't want it so I can repair other boats for someone who might not have money for a new solenoid.
To repair the solenoid I disassemble the terminals from inside and clean the internal contacts using a wire wheel then reassemble. You have to be careful doing this though if you decide or else it's easy to break the two thin wires inside for the magnetic coil, sometimes it's not possible to repair them but often it is depending on how the solenoid was made.