In the stock version of Kissmetrics on Tealium a purchase event is only meant to take place if an order id is set however one is being set with undefined order values on every page load regardless (even with absolutely no mapping performed). I can see the duplicate network request happening and on a custom implementation of Kissmetrics this issue doesn't happen.
Is this a known issue and is there a fix?
I just had a look at the template code, and I can see a very minor bug, which is very easy to fix. We'll get this updated in the tag marketplace, and in the meantime I'll PM you with a fix.
Check out our new Swift integration library for iOS, macOS, tvOS and watchOS: https://github.com/Tealium/tealium-swift with updated documentation https://community.tealiumiq.com/t5/Swift/tkb-p/swift.