Build failing with browserslist query as cover 66% in Create react app

Question

    "production-legacy": [
      ">1%",
      "last 4 versions",
      "Firefox ESR",
      "not IE < 9",
      "not ie_mob < 9"
    ],
    "production-modern": [
      "cover 66%"
    ],
    "development": [
      ">1%",
      "last 4 versions",
      "Firefox ESR",
      "not IE < 9",
      "not ie_mob < 9"
    ]
  },

The above is my browserslist configuration in package.json

I am using

"react-scripts": "4.0.3",
 "@craco/craco": "6.4.3",

The build command that I run is

BROWSERSLIST_ENV="production-modern" GENERATE_SOURCEMAP="${generateSourceMap}" craco build

When I run the above , my build fails with error as

[13:21:13] Error in 'BROWSERSLIST_ENV="production-modern" GENERATE_SOURCEMAP="false" craco build && mv build modern-build' -
Error: Command failed: BROWSERSLIST_ENV="production-modern" GENERATE_SOURCEMAP="false" craco build && mv build modern-build
The following changes are being made to your tsconfig.json file:
  - compilerOptions.paths must not be set (aliased imports are not supported)


    at ChildProcess.exithandler (node:child_process:397:12)
    at ChildProcess.emit (node:events:390:28)
    at ChildProcess.emit (node:domain:475:12)
    at maybeClose (node:internal/child_process:1064:16)
    at Process.ChildProcess._handle.onexit (node:internal/child_process:301:5) {
  killed: false,

but if I change the production-modern browserslist query to be "cover 99.5%" , it works.

Need to know why is this so ? cover 66% or cover 66.6% should also work the same way.