You may want to try and rotate the House and Unit Code dials. To verify they are making a good connection. We have seen some reports of the address not matching the dial settings.
What model switch is it and is it new enough to have soft start and remember the last local paddle dim level?
Does the companion switch or the switches paddle control the module in question?
What version of AHP do you have?
Any new or moved electronics in the home?
Jeff has a great set of tutorials on X10 and troubleshooting that may hep you.
https://jvde.us/x10-troubleshooting/