95% of the time, if you have issues with this, it’s due to the reverse module’s dedicated breaker tripping, thereby rendering the module inoperable, and you unable to shift. Follow this guide to locate the breaker, reset it, and see if this resolves your problem.
https://www.facebook.com/groups/ChaparralVortexBoatOwners/posts/2921494384822961/
If the breaker trips again, or does not resolve your problem, you may have issues with the iNR module itself; please make a post in the group, others will assist you in troubleshooting and figuring out the issue. (Note that low battery voltage is a main cause of this, see FAQ regarding the most important thing to do to keep your Vortex running right!)