Low Memory: Resource load fail, texture fall back

Trying to load texture packs in Minecraft but they won't load correctly. Minecraft only uses under 4Gb of ram. No way of setting it to use more. I have 32Gb total with 25Gb free. I've tried uninstalling and reinstalling. And looked at joining the beta preview but there is no option for that anymore (at least in the Xbox insider app). Why will MCPE not use more ram? when will an option be added that allows you to set limits?