We understand that your issue is isolated with the alarm on your IHome device. Please note that we have very limited support on third party speakers with built-in Google Assistant like IHome.
You may also try these steps to manually remove the alarm:
If the issue persists, it is best to report this with IHome support for better assistance. We'll be locking the thread in the next 24 hours, but if you still need assistance with any Google Home/Google Nest devices, feel free to start a new thread in the Community and we’ll be happy to help.