In case this trips anyone else up:
When setting up the proxy in the vue.config.js file, the port number needs to match the port that the asp.net app is listening to - this is defined in launchSettings.json - applicationUrl.
In your example "target: 'https://localhost:**7153**'," in vue.config.js should match
"applicationUrl": "https://localhost:**7153**;http://localhost:5226",
In case this trips anyone else up:
When setting up the proxy in the vue.config.js file, the port number needs to match the port that the asp.net app is listening to - this is defined in launchSettings.json - applicationUrl.
In your example "target: 'https://localhost:**7153**'," in vue.config.js should match
"applicationUrl": "https://localhost:**7153**;http://localhost:5226",