I want a sandboxed test environment that is *always* an exact copy of Production

I'm having an issue with a web application I am responsible for maintaining.

The system experiences regular bugs, and our support vendors are always asking us to see if we can "replicate the error in UAT". This is obviously a reasonable request. A lot of the time, for various reasons (some of which are clear, some of which are not), these errors are not present in UAT. This lack of bug reproducability in a testing environment is adding huge amounts of friction to the bug resolution process.

There are 3 key pieces of our system architecture where these bugs are flaring (the CMS, the API layer, and the database). I am proposing we set up a system job that perpetually clones these 3 parts of the system in to a sandboxed test environment. This cloning would happen periodically (eg, once every 24 hours), and automatically.

Is there a technical term for this sort of environment? Is this an established method of helping diagnose system issues? Is there somewhere I can read up on the industry best practices for establishing something like this? Thanks.