Hello,
Take our apologies for the delay in answering. We have a lot of requests these days.
1) What device do you use? Could you, please, provide us with video of the issue? Try to check the site using an incognito window.
2) I don’t see any issues with the selector or add to cart button https://gyazo.com/a632b1d26de5931b2a6cb7eab0c4979b Provide us with video of the issue.
3) Currency switcher just was missing in widget area. Readded the widget. Check bnow, please.
Regards