If you're having trouble using your Cash App account, you may have accidentally breached the app's terms of service. This could have happened because you accidentally logged in on multiple devices. The best way to resolve this is to contact customer support to learn how to reopen a closed Cash App account. Listed below are steps you can take to ensure that your Cash App account is still active. You may also want to try logging in to your account from another device.
If your Cash App account closed, you can reopen it. To do this, log into your account and select the profile icon. Then, click on "Support" and follow the steps outlined. You'll have to verify your identity and you'll have to confirm your payment method. You'll have to be logged in with a verified account before your Cash App account will reopen.

For more info: https://www.abidapps.com/why-cash-app-account-closed/