Wave does not always handle foreign currencies using the best methods. For example, Wave does not allow you to record a payment from one of your synced Bank Accounts to be recorded against an invoice.
Fortunately, since Wave is free to use and taxomate does not charge for attaching additional accounts, you may consider setting up a new Wave and connect a taxomate account for each Amazon/eBay/Shopify marketplace.
This may be particularly helpful if you are receiving payments from Amazon/eBay/Shopify in more than one currency. For example, you have a USD Bank Account for Amazon.com, a GBP Bank Account for Amazon.co.uk, CAD Bank Account for Amazon.ca, etc.