To fix the conflict between BSSCommerce Ajax add to cart and .scss theme (ie: ControllerModz), please follow our guide as below:
1. Add folder /home/controllermodz/public_dev/app/design/frontend/ControllerModz/ControllerModz/Bss_AjaxCart/ with the code in the link:
https://drive.google.com/file/d/1xTnlwErNONiGhltHeI-e76-bVm4GEVxp/view?usp=sharing
2. Run: php bin/magento setup:upgrade
3. Run: php bin/magento setup:static-content:deploy
If you have any questions, please contact us at sales@bsscommerce.com