Hi Timmise,
Thanks for the response. I think in this case square brackets ‘[]’ are added for checkbox options rather than commas and as far as I can tell makes it so you can’t check it as a parameter for conditions. For your Storefront link it renders checkbox filters of multiple inputs of the same attribute differently than on Bricks, please see screenshots below.
The Storefront for attributes adds them to the same group like with green and black selected in the URL it is filter_color=black,green. But with Bricks to select two brand attributes it is ?b_pa_brand%5B0%5D=16&b_pa_brand%5B1%5D=44. What it is trying to do is be ?b_pa_brand[0]=16&b_pa_brand[1]=44. Either way for conditions it cannot check for b_pa_brand, b_pa_brand[] or b_pa_brand[0] as a parameter. While if you change the checkbox to a radio selector, it works fine in the URL and can work with conditions, so the issue is with checkbox as a selector for filters.
I hope that may make things clearer.
Regards,
Perks