There is dumb thing that i couldn't find fix for it, that my items in pilgrim outpost that i bought isn't showing in the player stash after migrating from PS to PC (I linked the steam account in the pilgrim outpost)
#My Items In Pilgrim Outpost Aren't Showing In The Player Stash
lunar basin
rare smelt
I've had similar issues, the pilgrim outpost is very buggy unfortunately, some say that items redeemed on the outpost before the platform was linked will NOT show up in the stash unless the platform was linked BEFORE it was linked, but I know from experience that it isn't true. Only thing I might do is use the same email on your steam and use it also on your pilgrim outpost but I have no idea if it'll work, as I said it's random, sorry for your issue man 🙁
Before it was redeemed, sorry I made a typo, items redeemed before the platform was linked will not show up, at least I've heard
stray spire
my Outpost is stuck on 3 days ago ,busy weekend party at the Outpost and I wasn't invited 
lunar basin
Sad