Keeping the settings but losing the links would seem to eliminate an inadvertent factory reset of the EZIO8SA. Do you have the ability to run the SHN Utility Suite program. Requires a PLC or EZSrve/EZBridge to communicate with the powerline. If you can run this free download, try displaying each link record individually. That is, Display link records starting at record 1, then starting at record 2, and so on. If something changed the flag byte of the first link record to 00, it would appear that all the link records are gone when only the first link record has a problem.