We have a new site for a client that we are using the multicurrency feature. We have also set the manual conversion rate as the client monitors this themselves.
It works fine with the shopify payments. Showing up as the presentment currency and correct value all the way through.
But if the client chooses to pay by the manual payment method we set up "Credit account" then at the very last moment the currency switches back to our local (GBP) and an undefined conversion rate (looks like the live rate if you compare to xe.com) is used. Not the manual rate we set.
Does the manual payment method not work the same way? Given the whole site and checkout is correct up until the last moment this surprises me.