Bike starts "every second" time only....

[Black Warrior]

Thank you so much for your all replies!
I will check everything again starting from battery connectors (even though I have checked 'em several times... )
@ Gz Rider: I thought already about relays, but concluded if starter turned therefore they should have been ok. Still thanks so much for your ideas about the second relay - definitely swap 'em and see what's going on !