This seems to be caused by the Entity#teleportSpectators method calling serverPlayer#setCamera(null) after teleportation when it should probably be calling serverPlayer#setCamera(this) to set the spectator camera on the original entity again.
Entity#teleportSpectators
serverPlayer#setCamera(null)
serverPlayer#setCamera(this)
This seems to be caused by the
Entity#teleportSpectatorsmethod callingserverPlayer#setCamera(null)after teleportation when it should probably be callingserverPlayer#setCamera(this)to set the spectator camera on the original entity again.