Req. Category Specific Custom Field Alway Required

-- HikaShop version -- : 2.4.0
-- Joomla version -- : 3.4.1
-- PHP version -- : 5.4.40
-- Browser(s) name and version -- : any
-- Error-message(debug-mod must be tuned on) -- : None

We've have a custom order field setup set for a specific a category only.

It has worked fine since the site launched with 2.1.x a couple of years back.

However we have found with the 2.4.0 upgrade, that althougth the custom field may not be displayed, it is always being required.

If you put a product in that is not in the custom fields category and try go to the next step in checkout (to payment in our case), it does nothing. No error. It just takes you back to the same step you were on before (3 in our case).

Now if you add a product that the required field applies to, you can enter a value for the field and proceed.
You can then go back to step 1 of checkout, remove that product, and proceed with a product that is not in that category.

The cart apparently is keeping the "required" field value even thought it isn't being displayed any more.

We have plenty over orders where over the past 2 years that it worked just fine.
That is the field only displayed and was only required when a product in the select category was in the order.

Now it is being required on all orders regardless of the products in the order yet is not displayed nor gives an error message.

I just uploaded today (6/2/2015) the latest version of 2.4.0 and the problem persist.
I thought it might related to another issue I saw here but apparently not.

I believe I followed instructions from here on the forum to do it way back when. I'd have to hunt them down again as I don't think it was a post I contributed too. It was the first Hikashop site we did a 2+ years back but I would think modifications would have been in a view and not actual to a file on the server itself.

My only guess is the updates overwrote the modifications but if you are aware of the issue and working on it, then we can wait.

There are so few such orders where the products in question are ordered alone, it isn't a big deal at this time.

I've reviewed the checkout views and I don't see anything in any of the customization that are still there that might do this.

The view version actually got back to version 2.1.3 and 2.2.1, so a bit longer than I remembered.

There is a customization for "step" but I don't see anything that would deal with fields.
I would have expected it under custom_fields but that is stock.

Any idea other view where you think something like that might be? I just looked under checkout views as I didn't think it would be any where else.