Quantity calculator formula wrong

Hello @kassikoff

Please send a link to the subpage with this product and a screenshot of its Flexible Quantity settings.

Hello @kassikoff

I did not reproduce the same error on a clean test installation with the latest version of the plugin and WooCommerce.
The error is visible on the product page but not in the checkout – which suggests that there is another plugin in the store that changes the price on the product page.
Please disable other plugins (for a moment) and see if the problem persists. Use e.g. the HealthCheck plugin which allows the admin to enable the troubleshooting mode (so that disabling plugins is not visible to the store user). Or check it out on the staging site.