One of my rings replaced overnight

Last night my character was wearing an amethyst ring in the right slot - today when I logged in it is a sapphire ring, with a veiled mod on it to boot.
Seriously thought I was losing my mind but nope, checked a clip from last night, the ring changed. And I don't equip items with veiled mods anyway.
Just when I thought I'd seen all the ways this game can bug out...