Using the plugin with SWIFT cache plugin, creates issues

I marked sessions, and we are not using the JS changer. So it should have been good, right?
We are not using any extra layer of cache (varnish/cloudfalre).
When changing the currency, it does change for that specific page, but going to other pages, we are getting the prices with a previous currency.
Advice will be very appreciate, as we want to go live.
Thanks
Daniel