I think I mentioned this before & it's happened to 2 of my Rockets now...
The wire from relay goes to a plug behind the engine ( it comes out of loom ) & that wire ( Black ) goes directly up to starter relay.
That plug goes bad as it almost impossible to get at to clean let alone take apart.
Both bikes were randomly clicking...rock in gear & at some stage they would always start. I had cleaned & checked everything else before discovering this.
Fix is doing a direct wire from starter solenoid to Black wire in starter relay. Both bikes start every time now.
Mite not work for everyone but something to check at least.