Hey there, This is a known issue. Bungie is aware and actively investigating. [quote]• Allegiance Quest: We are investigating an issue where players cannot progress past Spider's Black Market in the Allegiance quest.[/quote] https://www.bungie.net/en/Forum/Post/252327934/0/0/1 Stay tuned to official Bungie sources for updates on the matter. Sorry to hear any inconvenience.
Known issue. Has been “months”, as it just started being bugged with Season of Opulence.