Greetings! This is a known issue and Bungie is investigating a way to grant the extra mod slot to existing armor pieces. [quote]ARTIFICE ARMOR MOD SLOT CLARIFICATION With the release of Hotfix 4.1.0.2 we have partially resolved an issue causing Artifice armor to lose the Artifice mod slot at the start of Season 17. Newly acquired Artifice armor will now successfully have the mod slot available, however we are continuing to investigate a fix for existing armor pieces that previously lost their Artifice mod slot.[/quote] via the [url=https://www.bungie.net/en/Explore/Detail/News/51446]6/9/2022 TWAB[/url].