Evaluate [related] fields

I have a custom post-type “containers”. Each container has an ACF relationship field called “acf_items” that can link to “item A” and/or “item B”.

Inside a specific container page, I want to display what item is contained in it (let’s say “item A”) but I also want to say what other items are available and not on display (in this case, “item B”).

Accordingly, I tried the following:

[loop type=containers]
 [if field=title value='Container of Choice']
  [related acf_items]
    [-if field=title value='Item A']  
     This container only includes [field title].
    [/-if]
    [-if field=title not value='Item A']  
     Other items not in this container are: [field title].
    [/-if]
  [/related]
 [/if]
[/loop]

The code produces no result, as if the related items are not being evaluated one by one against value.

I also tried to work around it by using vars:

[loop type=containers]
 [if field=title value='Container of Choice']
  [related acf_items]
  [set item][field title][/set]
  [pass vars]
   [-if var=item value='Item A']  
     This container only includes {-ITEM}.
   [/-if]
   [-if var=item not value='Item A']  
     Other items not in this container are: {-ITEM}.
    [/-if]
   [/pass]
  [/related]
 [/if]
[/loop]

This, too, produces the same effect: nothing gets displayed. Yet, the [related] routine correctly outputs two separate values: “item A” and “item B”.

It’s the [if] that doesn’t seem to do either comparison.

Thanks for your help