Q. We have some doors that we installed and they fit perfectly. Now, they have shrunk and no longer fit securely.
A. First, are you certain that the doors actually shrink, or did perhaps the frame move or expand and cause the doors to no longer fit tightly?
Assuming that the frame is perfect and has not moved, then the big question is, “Were the doors too wet for the environment or was the environment too dry for the doors?”
In either case, we know for certain that it is a moisture issue, as moisture is the only factor that makes wood move. If indeed the environment is drier than expected, you should not be held responsible, unless they told you prior. If the environment is normal, then we expect that the doors were too wet for a normal environment and this is an issue with your manufacturing. Or maybe your manufacturing was perfect, but after the doors left your facility they were mishandled.
Do you know the humidity in the environment now and is it the norm? Did you check the moisture content and control the moisture or the manufacturing environment? Such moisture and humidity measurements can be very useful in situations like this. It helps show that moisture changes after your manufacturing are not your fault.