SQL Server 2019 (RTM) - 15.0.2000.5 period has expired after upgrade to CU 8
In the version output you provided it states that you're running the Enterprise Evaluation Edition. This edition can only be used for a short period (I believe 180 days) before it expires and cannot be used. It can also never be used for production workload as per the license agreement.
For Production/DR
If you have previously purchased SQL Server licenses, you need to download your product key from the licensing portal and then follow these instructions to apply the product key to your instance of SQL Server.
If you have not purchased licenses, speak to your licensing reseller to obtain licenses, then follow the instructions to update your license key.
NOTE: You can upgrade your evaluation license to Enterprise, Standard or Web Edition of SQL Server depending on your requirements and available licenses.
For UAT
Follow these instructions for upgrading your edition, but instead of applying a license key, select Developer Edition, which is free for non-production workloads.