Nus is having issues with Google and his Duo app. Leo says that click on the three dots in the right-hand corner and it will show what account users are signed in with. It's possible that Nus signed out or removed his account accidentally. Nus says it doesn't remember it and tells him "something went wrong." Leo says that usually means it can't write to it. He recommends uninstalling Duo and reinstalling. Leo also recommends going into the phone app settings and look under the DUO app for clearing storage and cache. That will wipe it clean and start over.
Nus' phone is a Huawei phone and it could be that it can't use Google services anymore due to issues with the Chinese government and security. The good news is that the Google Pixel 4a is about to come out and the Pixel 5 a month later. It would be a good time to upgrade.