Is Lumenok the only lighted nock available for the Excalibur Diablo 18-in bolts? I see mixed reviews for this lighted nock. Can I trust it?

I'm not sure if it's the only option, but I have shot Lumenoks out of my crossbows for several years without any issues. In my experience, most of the time the problems are caused by user error. If your errors are prepped properly and the nocks are installed right, they should work every time.