Secondary Domain Showing Security Certificate Warning

Thanks for reading. We moved recently changed our primary domain name from net.au to com.au. We want to maintain the original .net.au to point to the same website. In cpanel we have com.au set up as the default domain and have net.au as a parked domain with a redirect on this to ensure the user always ends up at com.au. Since the change, when a user types into the browser ".net.au", they receive a security warning to indicate site is not secure. If I click through the warning to proceed, it correctly redirects to .com.au We do have SSL certificates for BOTH domains, but as I understand it we cannot use SSL for alias/parked domains? If I also understand correctly, alias/parked domains are the correct way to point additional domains to the same website? I noticed when typing in the .net.au address, it is trying to apply https so it looks like "force redirect to https" is on the domain - I can't see a way to turn this off in cpanel? Can you advise how I best set this up so that when the user types in the .net.au address, it redirects without security warning to .com.au Thank you!