DO NOT REPORT AN ISSUE IF YOU HAVEN'T TESTED THE ISSUE WITH THE LATEST VERSION IN CURSEFORGE

Functional Storage Version:

Titanium Version:

Crashlog If Applicable (Upload to pastebin/gist):
Item.of('functionalstorage:oak_4', '{Tile:{ForgeCaps:{},drawerOptions:{"Advanced: INDICATOR":0,TOGGLE_NUMBERS:1b,TOGGLE_RENDER:1b,TOGGLE_UPGRADES:1b},handler:{BigItems:{0:{Amount:0,Stack:{Count:1b,id:"minecraft:air",tag:{ISB_Spells:{data:[],maxSpells:1,mustEquip:1b,spellWheel:1b},data_model:{}}}},1:{Amount:0,Stack:{Count:1b,id:"minecraft:air",tag:{ISB_Spells:{data:[],maxSpells:1,mustEquip:1b,spellWheel:1b},data_model:{}}}},2:{Amount:1,Stack:{Count:2b,id:"functionalstorage:oak_4"}},3:{Amount:1,Stack:{Count:2b,id:"minecraft:diamond"}}}},hasDowngrade:0b,isCreative:0b,isVoid:0b,mult:1,storageUpgrades:{Items:[],Size:4},utilityUpgrades:{Items:[],Size:3}}}')
Item.of('functionalstorage:oak_4', '{Tile:{ForgeCaps:{},drawerOptions:{"Advanced: INDICATOR":0,TOGGLE_NUMBERS:1b,TOGGLE_RENDER:1b,TOGGLE_UPGRADES:1b},handler:{BigItems:{0:{Amount:0,Stack:{Count:1b,id:"minecraft:air",tag:{ISB_Spells:{data:[],maxSpells:1,mustEquip:1b,spellWheel:1b},data_model:{}}}},1:{Amount:0,Stack:{Count:1b,id:"minecraft:air",tag:{ISB_Spells:{data:[],maxSpells:1,mustEquip:1b,spellWheel:1b},data_model:{}}}},2:{Amount:1,Stack:{Count:1b,id:"functionalstorage:oak_4"}},3:{Amount:1,Stack:{Count:1b,id:"minecraft:diamond"}}}},hasDowngrade:0b,isCreative:0b,isVoid:0b,mult:1,storageUpgrades:{Items:[],Size:4},utilityUpgrades:{Items:[],Size:3}}}')
The two drawers store exactly the same items, but their NBT data is different.