[1.21.5] Custom block entity doesn't update inventory until right click or saving and reloading the world

Hello,

New to modding, but have a solid CS foundation. I've created multiple custom BlockEntities that all have the same issue, which is that the inventory only updates on right click (overriding the useItemOn method). I've seen multiple posts on here outlining a similar issue to mine, but I've already implemented the solution of: overriding the correct methods in the BlockEntity class and calling setChanged(). I've tried every different place for setChanged() to no success. I'm wondering if I'm missing something else or if there was some change to sending data to the client in 1.21.5? Or will I have to use a custom packet sender? Here is the code for one of my BlockEntity classes with a single inventory slot:

public class MyCustomBlockEntity extends BlockEntity {

    public final ItemStackHandler inventory = new ItemStackHandler(1) {

        @Override
        protected int getStackLimit(int slot, @NotNull ItemStack stack) {
            return 1;
        }

        @Override
        protected void onContentsChanged(int slot) {
            setChanged();
            if (!level.isClientSide()) {
                level.setBlockAndUpdate(getBlockPos(), getBlockState());
            }
        }

    };


    public MyCustomBlockEntity(BlockPos pPos, BlockState pBlockState) {
        super(ModBlockEntities.MY_CUSTOM_BE.get(), pPos, pBlockState);
    }


    public void clearContents() {

        inventory.setStackInSlot(0, ItemStack.EMPTY);

    }

    public void dropItem() {

        SimpleContainer inv = new SimpleContainer(inventory.getSlots());
        inv.setItem(0, inventory.getStackInSlot(0));
        Containers.dropContents(this.level, this.worldPosition, inv);

    }

    @Override
    public void setRemoved() {
        dropItem();
        super.setRemoved();
    }

    @Override
    protected void saveAdditional(CompoundTag pTag, HolderLookup.Provider pRegistries) {
        super.saveAdditional(pTag, pRegistries);
        pTag.put("inventory", inventory.serializeNBT(pRegistries));
    }

    @Override
    protected void loadAdditional(CompoundTag pTag, HolderLookup.Provider pRegistries) {
        super.loadAdditional(pTag, pRegistries);
        inventory.deserializeNBT(pRegistries, pTag.getCompound("inventory").get());
    }

    @Override
    public Packet<ClientGamePacketListener> getUpdatePacket() {
        return ClientboundBlockEntityDataPacket.create(this);
    }

    @Override
    public CompoundTag getUpdateTag(HolderLookup.Provider pRegistries) {
        return saveWithoutMetadata(pRegistries);
    }
      
}

Mostly encountering the issue when calling the clearContents() method anywhere outside of useItemOn() in the Block class. I've also tried overriding both the handleUpdateTag() and onDataPacket() methods, calling their super along with loadAdditional(), but neither changed the outcome. Thanks in advance for any replies.