1ST WE NEED MORE INFO on your drive train setup bruh , tranny model, clutch information, cable or hydraulic system, boosted or n/a , oil thickness, miles on the tranny if available, oem b1e shift linkage or 00' linkage, alot of factors that can contribute to a failure shift , none of us here are aliens that can know a specific error to cause this issue so the more info you give the better/specific feedback you'll get