Wrong modem on app

Tech came out due to multiple drops. Internet service started to drop off and on since sometime last week. Anyway, didn’t find an issue with the cables or wiring and decided to replace the modem. After he was done, I noticed the modem listed on the app was not correct so I let him know. He said it may update later on. I’m receiving internet offline errors in the app and now the service is back off again. I want to update the app with the correct modem first to see if that helps the issue. I restarted the gateway twice already. No success. Please advise.