3.0.3 - Google Analytics Add-on causing 30-40 second delay when submitting order

As the title says…

We have enabled the google analytics add on and entered the correct UA number as per the KB.

Site works fine, except when submitting an order (any payment method) it takes 30 or more seconds to complete.

As soon as we disable the addon - it is much quicker - close to instant.

Any ideas?