Various skin packs are missing from the Character Creator

Various skin packs are missing from the Character Creator. The only way to access them is going to the My Content section in the Marketplace.

Affected skin packs:

• 4th Birthday Skin Pack
• 5th Birthday Skin Pack
• Battle & Beasts
• Legacy Skin Pack
• MINECON 2016 Skin Pack
• Skin Pack 1 - Classic
• Strangers - Biome Settlers 3
• probably more

Steps to reproduce:

1. Go to Dressing Room -> Create Character/Change Character/Change Classic Skin -> Classic Skins.
2. Scroll down the list and press the Show More button until you've scrolled through all of your skins.
3. Now go to Marketplace -> My Content.
4. Search for any of the affected skin packs.

Observed result:
The skin pack is missing from the Character Creator, but is available to use in the My Content section of the Marketplace.

Expected result:
The skin pack is available to use in the Character Creator.