Heya! i can help with some information as not sure when acid will be back (am a mate of his) we played together a lot back in the past myself finishing sinnoh and him quitting the first time when he got to the elite four, i returned not to long ago and convinced him to return to play, when he sync his account with silver server he has lost all his badges up to sinnoh elite four, has been ported back to pallet town, his main team pokemon have been replaced with some other pokemon but his storage in the PC is correct. Seems like his progress he has made has all been lost, he can't use any pokemon as they are region locked to kanto though he is in kanto. Feel like its sync the wrong data from both servers so like his progress from the other server over his main progress but he has retained the correct money and storage pokemon
Thanks for your time