In Stock status suddently not working

Hi
I have had your filter for a while and it was all working perfectly. It was really good as we have many categories and a product can be in a few, and so this filter is great for us.

We have a seasonal product and run out of things at this time of year and so we need to direct our customers to the products that are in stock.

I know this was working correctly this week – I use it frequently when telling customers what to buy.

It suddenly now does not work and I have removed it from our filter – I can add it back on when you look. It was not working for either in stock or out of stock.

We had in stock and out of stock to be searchable – as customers like to browse our full range and plan for the following year.

We have not added any new plugins recently, nor changed anything

Thank you
Amy

The page I need help with: [log in to see the link]