Hi @hensterrsa,
That is quite weird. I’d first try ruling out conflict testing. The best way to determine if the issue is being caused by a theme and/or plugin is to:
1. Temporarily switch your theme to the Storefront (https://woocommerce.com/products/storefront/) or TwentySeventeen (https://www.ads-software.com/themes/twentyseventeen/) theme.
2. Try to reproduce the problem. If the problem is resolved, it is a theme conflict. If not, continue to the next step.
3. Temporarily deactivate all plugins except WooCommerce. You can do this manually or use Meks Quick Plugin Disabler (https-//www.ads-software.com/plugins/meks-quick-plugin-disabler/).
4. Try to reproduce the problem again. If the problem is resolved, it is a plugin conflict.
5. Reactivate each plugin one by one, testing after each, until you find the one causing conflict. That will be the culprit and contacting the developers/support team of that plugin is recommended.
If you do not want to interrupt your live site during testing, you can clone your site to a staging environment and perform tests without modifying your live site or impacting customers. Many hosts provide staging facilities, so it’s worth checking in with them. It’s also possible to do it using the free WP Staging (https-//www.ads-software.com/plugins/wp-staging/) plugin.
As always, backing up your live site before any testing and updates is highly recommended.
Hope that helps!