Vlliage

I am confirming that this is still a prominent issue in v1.21.131, however the “more severe” symptoms that @cmdcorp6534 described appear to no longer be an issue.

Packs can still be imported by closing the game and opening the file, but if the game is already running it still wont import.

For now there is a workaround

you can add a custom component to the item with the onUseOn event
(you would have to get the block using a method like this however)

onUseOn: e => {
const block = e.blockFace == 'North' ? e.block.north(1) : e.blockFace == 'East' ? e.block.east(1) : e.blockFace == 'South' ? e.block.south(1) : e.blockFace == 'West' ? e.block.west(1) : e.blockFace == 'Up' ? e.block.above(1) : e.block.below(1)  
}

Note that this event triggers after the block is placed, but before the itemStack is updated