I've recently "upgraded" from my S9 to the S21 5G. On the S9, the Samsung CAC "smart" air con controller app worked fine after months of complaining the schedule function crashed the app. But for 2021 Samsung seems to have resolved this problem and the CAC app worked perfectly on my S9 and my ancient iPhone 7.
Since switching to the S21, the CAC app stopped working with the In-Home option. So I setup my AC unit on the SamsungSmartApplicances.com portal and used the Out-Of-Home option. This worked fine for a while but this week stopped with the error message "Login Failed". This morning I'm not able to log into the www.global.samsungsmartapplicances.com site and it fails to redirect me to anything that works.
It is frustrating that the "Smart" Things app is not backwards compatible and supports all generations of Samsung AC wifi kit. I have no choice but to use this old CAC app.
Well played Samsung, you played yourself. Your AC CAC app does not work on your flagship S21. Please fix this.