Nothing to do at the vendor or for the vendor, he just keeps blinking, indicating something needs to be addressed, but there’s nothing to address.
Plus I’m standing by him, but his map icon is by the stairs from the landing zone, not sure if that was always like that tho
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This is a known issue and happens soon as you collect a reward for ranking up. It will stop at reset until you rank up again and collect then will start again. Bungie has fixed it once but it still persists.