I am also experiencing this issue in 1.17.1. I can override the spyglass model that is held in the hand (spyglass_in_hand.json) as expected, but using the same method on the inventory texture (spyglass.json) does not work.
With further testing, it looks like the same behavior is true with glow berries. Harvest normally on dirt, do not harvest on farmland.
This issue is still present in 1.16.100 (iOS).
I am still experiencing this bug as well (on iOS). I cannot open the marketplace at all, and my character creator shows the same blank screen. On rare occasions I find it is working for like 10 minutes but then it will lose connection mid-session.
I have tried deleting and reinstalling the game, switching to mobile data, using a new Xbox account, and more, and nothing fixes the issue. I have had this going on for months, since one of the 1.18 updates. But it persists in 1.19.