I originally started playing on PC and paid for the shadowkeep deluxe which included 4 passes. I later began playing on XBOne and purchased shadowkeep and forsaken individually because SK explicitly stated that it included a season pass on the Xbox market where the SK/Forsaken combo did not. I'm still only seeing one additional purchased season from the season tab.
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Your Steam characters have the season pass according to the API for the current season. You also have cross save enabled, so when you log in on XBox you should be seeing your PC characters and thus you should also have access to the same season passes. Or are you trying to play D2 on another XBox account and not the one currently linked in this profile's cross save?