iPhone failures

So I added some devices to my app on android. Then added my mom’s iphone 11 to the group.

Able to see all the added devices. When I click on a device in her iOS app, it pops up a notification that I have to “Register the device to Smartthings”. But I already did that on the Android app.

Trying register my washer on the iOS app doesn’t work at all. I connect to the AP, but then absolutely nothing happens.

Why the hell can’t the iOS app just plug and play use the devices? She can see the remaining washing time etc. but the app forces a register step that doesn’t work at all.