Amasty Full Page Cache for Magento currently has compatibility issues with Codisto.

To resolve this, please add an exception for Codisto related pages so that Amasty Full Page Cache for Magento doesn't impact Codisto.

Steps

1. Go to the Full Page Cache settings
2. Find the Pages heading and then look in the Ignore List
3. Add an entry for /codisto/  (as per below)