babel-plugin-istanbul is not working properly in babel config file

[Jamesj001]

This issue is a bit strange one as the above statement is partially happening

Added babel-plugin-istanbul in babel config file like this :

plugins: [
        '@babel/plugin-proposal-object-rest-spread',
        [
          "istanbul",
          {
            "excludeNodeModules": false
          }
        ]
      ]

Explaining in detail :

So when I add the babel-plugin-istanbul in babel.config.js it works completely fine but if i add it in babel.config.cts in the same manner it's not working properly

So the only difference is in the extension of the 2 babel config files i.e. .js and .cts

Any clue how to fix this ?