Web screens data format

My customer has Sage 2019 PU4. They have web screens installed which they're only using for the CRM integration. However, the dates in the Sage screens in CRM are showing in MM/DD/YYYY. In CRM the user is UK English. Everything is set correctly for UK. In Sage, the ADMIN user and the CRM user are both set to English. The only other options are English (United States), English (Canada), English (Australia), English (South Africa). If the user is set to English, why are the dates in the wrong format?