I can see in your compatibility page that Foundation 6.4.3 supports IE9. (Ref: https://foundation.zurb.com/sites/docs/compatibility.html)
I'm using the legacy float grid and that seems to work fine, but accordions and tabs are not working in IE9. I can't find anything in your docs that points to specific tweaks for IE9 on those plugins. Anything I'm missing?
Any help is appreciated. Thanks.