Armasight Orion 5x problem

Cousin & I both have these scopes. Mines on a Hummingbird/Colibri, his on a Compact Cricket.. Mine’s perfect, but his changes POI after a while. Short of returning it, is there a quick fix that we can do? Scope really is well suited to our night rat hunting, 40 yards and in, and he wants to keep it..

Thanks for any help.

218bee