When going into Decorated Pots in Spectator Mode, the block renders black

Steps to Reproduce:

1. Run '/locate structure trial_chambers'
2. Go to coords shown
3. Find a Decorated Pot in the Trial Chamber
4. Run '/gamemode spectator'
5. Fly inside of a Decorated Pot

Observed Result:

The pot is black inside

Expected Result:

The pot is the same colour on the inside