No crank, no start

Vehicle won't start randomly when attempting to turn on. It will either won't crank at all or turn on right away. Battery is new. Fuel pump, injectors, coils and spark plugs had been replaced in the last 12 months. My vehicle has a manual transmission so when I depress the clutch all the way and attempt to turn vehicle on there is only dead silence, no click, no crank, nothing. All lights on dashboard turn on as normal, fuel pump primes (I can hear the humming) but nothing. I replaced the crankshaft sensor and still does the same. Checked voltage and alternator and all is good. Sometimes it starts right away (usually when it has been sitting for a while), and sometimes takes a lot of tries, and when it actually turns on, it does it as if there is no issue at all and drives perfectly good. There are no codes, no hesitation when running, no indication of a problem at all.