Hi,
It highly depends on how the filters were created. If that is some sort of a drop-down or other string input type ACF field, then it may not store the actualy number, but an object or string data. For example instead of “3” it stores “3 beds”. That of course will not work with a slider type, because that is not a numeric field. I will have to check to confirm.
I also need to test the bug, but when I tried to log-in, I could not. The admin details seem to be incorrect. Can you please check that?
The isotope script is a custom built derivation of the metafizzy isotope script, completely independent, in a different variable scope. It looks more like a timing issue to me. I could not test it though, as the plugin is currently disabled.