IsolatedIntegrationTests: ArgumentNullException thrown when executing tests against net5.0

I have a series of NuGet packages that targets Kentico, which provide helpers/utilities, and extension methods against the Kentico API. With the release of Xperience 13.0.5, I've been able to sucessfully build+run an Mvc project that targets net5.0. As such, I'm working on updating my NuGet packages to also target Xperience 13.0.5, however, I'm experiencing exception within the CMS.Tests APIs when executing my tests against net5.0. I find this strange, as these tests successfully execute (and pass), when ran against net48 and netcoreapp3.1.

The exception I am receiving:

 Message: 
    System.ArgumentNullException : Value cannot be null.
    TearDown : System.ArgumentNullException : Value cannot be null.
  Stack Trace: 
    Monitor.ReliableEnter(Object obj, Boolean& lockTaken)
    Monitor.Enter(Object obj, Boolean& lockTaken)
    TypeManager.get_IoCContainer()
    TypeManager.PreInitializeTypes(Assembly assembly)
    TypeManager.PreInitializeTypes()
    ModuleEntryManager.PreInit()
    AppCore.PreInit()
    CMSApplication.PreInit(Boolean initializeContainer)
    AutomatedTests.PreInitApplication()
    AutomatedTestsWithLocalDB.AutomatedTestsWithLocalDBSetup()
    --TearDown
    Monitor.ReliableEnter(Object obj, Boolean& lockTaken)
    Monitor.Enter(Object obj, Boolean& lockTaken)
    CultureSiteInfoProvider.ClearSiteCultures(Boolean logWebFarmTask)
    SiteModule.ClearHashtables(Boolean logTasks)
    ModuleManager.ClearModules()
    ModuleManager.ClearHashtables(Boolean logTasks)
    AutomatedTests.CleanUpDataContext()
    AutomatedTestsWithLocalDB.ReleaseDatabases(DatabaseProperties database, Boolean cleanupDataContext)
    AutomatedTestsWithLocalDB.AutomatedTestsWithLocalDBTearDown()

Notes:

• I am using IsolatedIntegrationTests
• I am using the AutomatedTests.InitApplication method to call ImportProvider.ImportObjectsData to seed the DB with test data from a Site Export Archive.