Fonts vary (eg, dramatic kerning) between being loaded from typekit.com and local CC sync

I'm not sure if this is a question or a bug. I noticed that when loading the font "Futura PT" in as a webfont from typekit, the kerning was completely off in places, most noticeably with the letter pair 'AY' when capitalised. When changing this from the web version ("futura-pt") to the version I've locally synced through Creative Cloud and thus being loaded from my local system ("futura pt"), the problem went away.

I wrote a tiny little HTML test page to show the discrepancy. The blue text is being loaded from my local cache, the red text is being loaded from the webfont. You can see this being particularly bad with "OX" and "AY". I tried the same thing with another font (Abril Text) and they also didn't line up, but this time it was a line-height issue rather than a kerning one.

What could be the cause of this? Is it an issue from Adobe's end or could I be somehow not loading the Opentype version properly? I'm using the bog-standard method of loading typekit and not doing anything special or weird.

Thanks in advance.