Welcome to SonarSource community, and thank you for your feedback!
Coming back to your original question, the code smells that have suddenly appeared in your project don’t denote a regression of the analyzer, but rather demonstrate what stated above, that is, an issue raised by TypeScript rule S4328. Therefore, they are not coming out of nowhere ;).
Currently, the analyzer does not consider any webpack configuration, and the aformentioned rule does not have a different semantic for the
@ symbol. We’ll discuss among ourselves if there is something to be done here and come back to you. In the meantime, you can configure the rule by providing a value to its
'@/mixins' should do the trick.
Hope this helps,