If you've recently created a Performance Max with a new Google Merchant account, you will likely have to verify your store address and phone number.
This is the case with every new Merchant Center account.
Your ads will be paused until you complete the verification process.
Identifying the issue
The issue can be identified by seeing an alert in your Merchant Center dashboard.
Resolving the issue
To resolve the issue, verify your phone number and street address.
This can be done by clicking Verify phone number in the red banner in your Merchant Center dashboard.