Everything started when a group from Latvia announced a DXpedition mid May that was cancelled in the last minute because they haven’t permission to operate there.
Mount Athos is a peninsula located in Greece with an autonomous government and populated with around 2000 Orthodox Christian monks. They have their own rules and, among them, visiting Mount Athos is restricted and only for males.
Regarding ham radio, it has a resident operator from 1988, Elder Apollo, SV2ASP/A, that uses to be on the air. He is quite proficient and he answers promtly to QSL enquiries (only direct by mail).
Anyway, Mount Athos is not more different than other DXCC entities with a very difficult access and you just need to be patient to contact it.
At least, Mount Athos appears almost every month and you can get the confirmation in a couple of weeks. But not in LoTW, according the LoTW Users List from HB9BZA, Mount Athos is the only DXCC entity missing.