Sold individually not applied to a certain variable options

I have a product with 3 variations, var 1 & var 2 can be bought together, but var 3 must be sold invidually.

At tab “Inventory”, I have unchecked “Apply Sold individually” option, but the for default Woocommerce option I checked “Sold individually” option.
And at tab “Variations”, for var 1 & var 2, I also have unchecked Apply “Sold individually”, but for var 3, I checked “Sold individually” checkbox.
But when I test at the shop page, I still can order var 1 or var 2, together with the 3 vars .

If I enabled “Apply Sold individually” option at tab “Inventory”, I can apply sold individually but for all vars.

Could you help me this issue please, thanks in advance.