Default Intelli Sense Engine has never really worked

[julienlavergne]

Environment

• OS and Version: Windows 11 Enterprise Build 26100
• VS Code Version: 1.104.0
• C/C++ Extension Version: 1.27.7
• If using SSH remote, specify OS of remote machine: Linux RedHat 8, 4.18.0-553.72.1.el8_10.x86_64

Bug Summary and Steps to Reproduce

Bug Summary:
There are so much things not working that I don't really know where to start with. We have been using VSCode for many years and we were never able to have the default engine to work.
We are using the Cmake extension and all information are provided through the compilation database file. CMake commands works file, most of the includes are found, but the code cannot be navigated.

The database is often under construction, but even when ready, Intelli Sense is usually unresponsive.
Some Include files are with red Squiggles, even though they are clearly present and in include paths.
Opening a file trigger an update that takes about 15 seconds, too long to quickly navigate the code since Intelli Sense is disabled during the update.
When hovering include files, it often triggers a parsing of open files. Some includes with red Squiggles can be clicked, some other cannot, it's pretty inconsistent.
Ctrl+hovering symbols in the code does nothing most of the time. And when it works, it shows a tooltip with "Loading...".
Ctrl+Click on symbols triggers a loading bar at the top of the workspace, but after a while nothing happens. When it finally ends, I can see hundreds of LSP: Request canceled by server (<unknown/completed>, code: -32802, id: ...) in the logs.

Ctrl+hovering symbols quickly in the code seems to trigger a high number of "request" that times out, but that's just my analysis. The remote machine is powerfull and not busy at all. Ping with this machine is 4ms. We do not have any latency issue with this machine when using SSH, and we are able to upload and download large files without any problem.

Configuration and Logs

`c_cpp_properties.json`

{
    "configurations": [
        {
            "name": "Linux",
            "configurationProvider": "ms-vscode.cmake-tools"
        }
    ],
    "version": 4
}


Let me know what kind of logs you need as there are a lot.

Other Extensions

Issue persist with minimal extensions:

Locally installed:

• Remote - SSH version 0.120.0

Remote:

• C/C++ version 1.27.7
• Cmake Tools version 1.21.36

Additional context

No response