Why VS Code intellisence for Unity is not working in Ubuntu?

I'm having a problem with intellisense on vs code for Unity on Ubuntu 22.04. I have a lot of extensions for vs code so that may be the problem.

I tried to open a file in Unity for vs code. Using external tools setting. It worked but I want to have intellisense too.

Normally this shouldn't depend on any other extension you have installed. Could you go through following checklist and confirm everything is setup correctly?

VSCode Unity 3D working IntelliSense checklist:

• Have the Mono Framework and .net SDK installed on your machine
• Make sure in Unity3D the external Editor is set to "Visual Studio Code" and press regenerated project files if nessacary
• Have the C# extensions installed in VSCode
• Either in the project settings or globally have omnisharp.useModernNet disabled
• Check if the Path to mono is correct in your VSCode setting for omnisharp.monoPath
• Ensure the OmniSharp Server is running when you open up the Solution

Further debugging

• Check the Output of your OmniSharp/C# Console in Visual Studio and check the error messages.

• There is a bug in the C# extension in Version v1.25.2 with Mono Path. I can work with v1.25.0 very fine so far.

I hope this helps you to find the issue on your machine. 😅