There are (2) issues here. First, did you look up the call sign AD4MY because you heard someone using that call sign to run a net on 40 meters? If so, that station was operating illegally. The call sign AD4MY has been vacated since November 1996 per my previous post.
The previous holder of AD4MY, Rod Wright, upgraded his call sign in November 1996 to WZ4X. I provided a link to his contact info on QRZ in my previous post.
The second issue is that eHam's callsign lookup is NOT a lookup of current FCC data. It shows the user's ALIAS, which could be an old call sign, a current call sign, or something else that may not even be a call sign. The ALIAS is user provided to eHam and is not pulled from any FCC data base.
When you entered AD4MY into the eHam callsign lookup you saw what that user's ALIAS is. If it was at one time a valid FCC call sign, it would not be automatically updated if the user updates their call sign. The user has to do that manually.
I hope this helps.