Repository: create-react-app
Issue: Dev Server does not always show typescript compilation errors
Labels: needs triage,issue: bug report

### Describe the bug

React dev server does not consistently display typescript errors. Frequently, when running `react-scripts start`, the compiler does not display typescript errors and I only see them when running `react-scripts build`. I have noticed that this happens more frequently when there is a typescript error in files that have not been modified or when the dev server is consuming more CPU. Any ideas on why this happens and how to address it?
 
### Did you try recovering your dependencies?

Yes 

### Which terms did you search for in User Guide?

"typescript errors" "typescript changes"

### Environment

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current version of create-react-app: 3.4.1

System:
    OS: macOS 11.2.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Binaries:
    Node: 12.7.0 - /usr/local/bin/node
    Yarn: 1.22.10 - /usr/local/bin/yarn
    npm: 6.10.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 89.0.4389.128
    Firefox: 85.0.2
    Safari: 14.0.3
  npmPackages:
    react: 16.10 => 16.10.2 
    react-dom: 16.8.6 => 16.8.6 
    react-scripts: ^4.0.3 => 4.0.3 
  npmGlobalPackages:
    create-react-app: Not Found


### Steps to reproduce

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1. Create a CRA typescript project of sufficient size (couple hundred files)
2. Run dev server
3. Trigger an error in a file you didn't change

### Expected behavior

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Errors show up in the console 
### Actual behavior

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Compiles without error
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