Troubleshoot Plugin Conflicts

We have a compatibility issue with plugins somewhere. I need help troubleshoot on staging / dev server. What happened is I have a date and time selector field for people to choose pickup date and time (using a plugin) when they decide to pick up instead of shipping, we minus shipping charge and customer does not need to input the address (It hides the address). Issues: - If I choose shipping: It will complain pickup date and time is required, see the first 2 screenshots and the video: [login to view URL] - If I choose pickup: It will complain billing name, billing address and billing email required, see the last 2 screenshots and the video [login to view URL] Response from Developers: 1. CartFlows response was "We logged in to your site and checked the pre checkout offer issue. It found that you have added the custom field from ThemeHigh, a third party plugin and which is required on the checkout page. Please see here: [login to view URL] You need to make sure that this field should not be required when the shipping option is 'Pick up at our office'. When you enable the Precheckout, and while placing the order, it checks for if all required fields are filled or not. And shows the error for that field." 2. ThemeHigh response was: "We have checked your website by deactivating all other plugins except the CartFlow plugin, Checkout Field Editor, and Elementor, we can see that the issue has been resolved. The issue might be due to conflicts of any other plugins installed on your website. As the issue is not there currently on the staging site you have provided to us after activating the deactivated plugins, we are not able to find which plugin is causing the conflict. In order to further look into your situation, could you please recreate the issue on the staging site so that we can immediately start working on it. "