Hey,
Please follow these steps to recreate the error message:
1. go to https://froxx.co.uk/shop
2. use the filters on the right-hand side to select the “blacks/greys” option
3. move to the 3rd page of clothing results
4. Change the colour filter to green
5. 404 error will occur
Preferably, we would like the customer to be navigated to the 1st result page for any given filter when they select the new filter option.
Thanks for looking into this.