WP-cron issues
CryptoWoo's order processing and exchange rate updates rely on WP cron, the built-in cron job service of WordPress.
The speed of the payment processing is directly dependent on the execution of WP cron.
The disadvantage of WP-cron is that it's only triggered if there are visitors on your website. This could lead to infrequent exchange rate updates from the cryptocurrency exchanges.
To ensure that the updates are triggered as defined, you should set up a cronjob at your hosting provider to hit wp-cron.php at a regular interval. Please see our tutorial How to Configure a Real Cron Job for CryptoWoo (Recommended).
Fatal PHP Errors
Any WordPress plugin, theme, or custom code can cause fatal PHP errors. When a fatal PHP error occurs, the server execution will stop. Each cron job runs events scheduled by plugins until completed. If a fatal error happens during any of these events before CryptoWoo is executed, no exchange rate updates or payment processing can be done because CryptoWoo has not had no chance to run yet. This may cause CryptoWoo to run very infrequently.
How to find a PHP fatal error
You can find the fatal errors log file by navigating from your WP-Admin to WooCommerce -> Status -> Logs. If it exists, then you will find a file called fatal-errors. This link may be helpful should you get stuck:
https://woocommerce.com/document/finding-php-error-logs/
Open the fatal-errors file and look for clues in the error message about which plugin or theme file is causing this. Disable the plugin or contact the plugin developers for assistance.
Were you unable to fix the issue?
Contact us at https://cryptowoo.zendesk.com/hc/en-us/requests/new, and please include a full description of your issue. You may also enable logging in the settings and download the logs after the issue occurs, then attach the log to your ticket. Also include the fatal-errors log from WooCommerce if you have it.