The Smarthings classic app is what has been around for a while. If you do a search for Smartthings in Google play store and such now it shows you the rebranded Samsung Connect app that was renamed to Smartthings some months back.
Eventually the Smarthings(Connect) app will be the app to use but it has a way to go for functionality. But it does have some good stuff. It has a new version of SHM that doesn’t show in the IDE and uses the new Smarthings API’s.
I am glad it worked today. One thing you need to remember with Arlo is that you can only have one thing connected to the arlo cloud at a time. Perhaps you have had a conflict there when it tries to change it.