VS Code IntelliSense not working for Unity3d

Problem: IntelliSense is not working for Unity specific methods and functions (i.e., Update, FixedUpdate, Awake, etc.).

It does work, however, for non Unity specific methods (i.e., IEnumerator, void, public, float, int, etc.) and for Unity specific variables (i.e., Gameobject, transform, camera, etc.) and Unity specific namespaces (i.e., UnityEngine, UnityEditor, Unity, etc.).

I am using: Visual Studio Code 1.41, Unity 3d 2018.4.15f1 (I have the same problem when using 2019.2.x).

I have tried the following solutions to no results:

1. Using different versions of .NET
2. Deleted vscode file within the project.
3. Uninstalled and reinstalled both Unity and Visual studio.
4. Changed <TargetFrameworkVersion>v4.7.1</TargetFrameworkVersion> to <TargetFrameworkVersion>(Currently installed version)</TargetFrameworkVersion> but unity automatically defaults back to v4.7.1

Possible problems:

1. The sln file the project creates reads

   Microsoft Visual Studio Solution File, Format Version 11.00
   # Visual Studio 2010
   Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Assembly-CSharp", "Assembly-CSharp.csproj", "{B2B58FB2-4462-6B0C-A872-40DD957E5FE0}"
   EndProject
   Global
       GlobalSection(SolutionConfigurationPlatforms) = preSolution
           Debug|Any CPU = Debug|Any CPU
           Release|Any CPU = Release|Any CPU
       EndGlobalSection
       GlobalSection(ProjectConfigurationPlatforms) = postSolution
           {B2B58FB2-4462-6B0C-A872-40DD957E5FE0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
           {B2B58FB2-4462-6B0C-A872-40DD957E5FE0}.Debug|Any CPU.Build.0 = Debug|Any CPU
           {B2B58FB2-4462-6B0C-A872-40DD957E5FE0}.Release|Any CPU.ActiveCfg = Release|Any CPU
           {B2B58FB2-4462-6B0C-A872-40DD957E5FE0}.Release|Any CPU.Build.0 = Release|Any CPU
       EndGlobalSection
       GlobalSection(SolutionProperties) = preSolution
           HideSolutionNode = FALSE
       EndGlobalSection
       GlobalSection(MonoDevelopProperties) = preSolution
           StartupItem = Assembly-CSharp.csproj
       EndGlobalSection
   EndGlobal
   

   For some reason, the sln file seems to be used for Visual Studio 2010. I do not know if this is intentional or if this is the problem.

2. When attempting solution 4, as stated above, Unity (or VS Code for all I know) automatically changes .NET version from whatever I manually typed to 4.7.1. I have 4.7.1 already installed so this may not be the problem.

Extra information:

Here is the omnisharp log:

Starting OmniSharp server at 2020. 1. 20. 오후 9:08:43
    Target: c:\Users\stpau\New Unity Project\New Unity Project.sln

OmniSharp server started.
    Path: C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\OmniSharp.exe
    PID: 2232

[info]: OmniSharp.Stdio.Host
        Starting OmniSharp on Windows 6.2.9200.0 (x64)
[info]: OmniSharp.Services.DotNetCliService
        DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Located 1 MSBuild instance(s)
            1: StandAlone 16.3 - "C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\.msbuild\Current\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        MSBUILD_EXE_PATH environment variable set to 'C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\.msbuild\Current\Bin\MSBuild.exe'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: StandAlone 16.3 - "C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\.msbuild\Current\Bin"
            CscToolExe = csc.exe
            CscToolPath = C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\.msbuild\Current\Bin\Roslyn
            MSBuildExtensionsPath = C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\.msbuild
            MSBuildToolsPath = C:\Users\stpau\.vscode\extensions\ms-vscode.csharp-1.21.9\.omnisharp\1.34.9\.msbuild\Current\Bin
[info]: OmniSharp.Cake.CakeProjectSystem
        Detecting Cake files in 'c:\Users\stpau\New Unity Project'.
[info]: OmniSharp.Cake.CakeProjectSystem
        Could not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
        Detecting projects in 'c:\Users\stpau\New Unity Project\New Unity Project.sln'.
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for 'c:\Users\stpau\New Unity Project\Assembly-CSharp.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in 'c:\Users\stpau\New Unity Project'.
[info]: OmniSharp.Script.ScriptProjectSystem
        Could not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: c:\Users\stpau\New Unity Project\Assembly-CSharp.csproj
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.EditorConfigWorkspaceOptionsProvider, Order: 200
[info]: OmniSharp.WorkspaceInitializer
        Configuration finished.
[info]: OmniSharp.Stdio.Host
        Omnisharp server running using Stdio at location 'c:\Users\stpau\New Unity Project' on host 8980.
[info]: OmniSharp.MSBuild.ProjectManager
        Successfully loaded project file 'c:\Users\stpau\New Unity Project\Assembly-CSharp.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
        Adding project 'c:\Users\stpau\New Unity Project\Assembly-CSharp.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Update project: Assembly-CSharp

How can I solve this problem? I also asked this question on both reddit and the Unity forums with no success.