If you are

1. using a NPM workspaces monorepo,
2. and the nested packages have a (dev) dependency on Typescript,
3. and you've upgraded the typescript version,
4. but npx tsc --version still shows the old version

For example:

$ cd <repo_clone_directory>

$ ls -1 packages/
micro-service-1
micro-service-2
ui-1
ui-2

$ npx tsc --version
Version 4.9.5

Then you probably need to ADD a (dev) dependency on Typescript in your top-level package.json file.

$ cd <repo_clone_directory>

$ npm install typescript

$ npx tsc --version
Version 5.2.2

And if your CreateReactApp package is complaining that your typescript version is not supported when ESLint runs, then you should

1. temporarily disable ESLint.
2. eventually migrate to vitejs as CRA has been abandoned.

From packages/ui-1/package.json

  "scripts": {
    "start": "DISABLE_ESLINT_PLUGIN=true react-scripts start",
    "build": "DISABLE_ESLINT_PLUGIN=true react-scripts build",

EDIT: Adding "typescript" to the top-level package.json also helps with minor version upgrades.