Texture/Mashup packs in Better Together are no longer available to all accounts on that XBox

I had purchased multiple texture/mashup packs for my kids to use on the old XBox One version of Minecraft.

Today, when they started playing on the Better Together version, I was able to redownload the packs with my main account, but those packs were no longer available to them to use with their accounts. I do not play Minecraft. I only purchased the packs for them to use together on our family XBox One.