For anyone experiencing issues with either the Smart Home or Smart Air Conditioning apps, I'd advise trying to connect your devices using the SmartThings app instead.
Our UK SmartThings site has helpful guides on how to set up appliances in SmartThings, as well as some troubleshooting tips, and contact details/links for the SmartThings team and the SmartThings Community here.
Just a couple of useful general FYI's to add, if you should encounter any SmartThings-related issues with your appliances:
just bought a WW10H9600EW washer... Disappointed beacause I couldn't connect it through SmartThings neither through SmartHome.
iPhone 6 running 12.1.4 firmware
Any suggestion? or better... any update to your apps or servers in the very next days????
Come on Samsung!!! You can do it