I am experiencing where all of the items dropped on the ground were hidden. I made a Loot Filter on my Shaman, then started using it on my Marksman. I have a lot of items hidden, but I am not hiding Affix Shards, yet Affix Shards are being hidden. I actually don’t have any rules regarding Affix Shards. If I press Z twice it will suddenly start showing the Affix Shards again.
This is a known issue. Thank you for the report.