How to indicate that validation checks whole section of form?

In our app we have few views that use backend validation, that sometimes might take more that a second to response. What is more unique about it, is that validation is sent for whole section. For example, providing value for Name, will trigger a backend validation for second field Code as well.

Currently there are no indicators that the validation is happening in the background. Only error will be displayed in case of invalid data.

So if the user provide value for Code field, before previous validation request is done, then its new value is not checked. It may result in incorrect errors, or lack of validating new value.

Since we cannot modify the way validation works (checking more than one field at the time), at least for now, we are trying to find a good way to show user, that something is going under the hood. We were thinking about adding the same loader that we use in other parts of app, when page is still loading, but it seems bizarre and not very UX friendly, that user would be seeing it, every time when he provides data:

On the other hand, user should not be able to provide data in that short timeframe, to ensure, that the data will be properly checked. What would be a good approach?