Resource packs won't deactivate

When a resource pack is active on a world, the ‘Remove’ button seems to work as normal, but the change is never saved.

Steps to reproduce: On the ‘Edit World’ screen, click ‘Resource Packs’, ‘Owned’, then activate a resource pack. Load the world and exit to the title screen. On the ‘Edit World’ screen, click 'Resource Packs', and then ‘Remove’ on the pack. Then load the world again.

Expected result: The resource pack stays unloaded and the world reverts to the global texture pack

Actual result: The texture pack appears to deactivate with a message [texture pack name] deactivated, and ‘No active resource packs’ on Local, but entering the world, or going back to the title screen, then back to the world’s resource pack screen shows the resource pack as still being active. Also, deleting the resource pack will just result in a prompt to redownload it when re-entering the world.