Application DLL cannot be loaded once hosting model is switched OutOfProcess

I have a .Net 8 web app deployed to an Azure app service. There are 2 components, and because one of them is deployed as a virtual application / sub-app, I had to switch to both components using the OutOfProcess hosting model (this is because both, mixed models and two InProcess models, errored out in Azure as not allowed). When I was only deploying the main app and it was using the InProcess model, it ran in Azure fine. As soon as I switched to OutOfProcess, they both error out on startup, with the error stack below in the logs.

What additional setup or configuration do I need in order to avoid this error and load all of the DLLs successfully when deploying OutOfProcess?

Error Stack:

Microsoft.AspNetCore.Hosting.Diagnostics: Application startup exception
System.IO.FileNotFoundException: Could not load file or assembly 'DVS.ServiceContract, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
File name: 'DVS.ServiceContract, Culture=neutral, PublicKeyToken=null'
at System.Reflection.RuntimeAssembly.InternalLoad(AssemblyName assemblyName, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext, RuntimeAssembly requestingAssembly, Boolean throwOnFileNotFound)
at System.Reflection.Assembly.Load(String assemblyString)
at Microsoft.AspNetCore.Mvc.ApplicationParts.ApplicationPartManager.<>c.b__8_0(ApplicationPartAttribute name)
at System.Linq.Enumerable.SelectArrayIterator`2.Fill(ReadOnlySpan`1 source, Span`1 destination, Func`2 func)
at System.Linq.Enumerable.SelectArrayIterator`2.ToArray()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.OrderedEnumerable`1.GetEnumerator()+MoveNext()
at System.Linq.Enumerable.SelectManySingleSelectorIterator`2.MoveNext()
at System.Linq.Enumerable.ConcatIterator`1.MoveNext()
at Microsoft.AspNetCore.Mvc.ApplicationParts.ApplicationPartManager.PopulateDefaultParts(String entryAssemblyName)
at Microsoft.Extensions.DependencyInjection.MvcCoreServiceCollectionExtensions.GetApplicationPartManager(IServiceCollection services, IWebHostEnvironment environment)
at Microsoft.Extensions.DependencyInjection.MvcCoreServiceCollectionExtensions.AddMvcCore(IServiceCollection services)
at Microsoft.Extensions.DependencyInjection.MvcServiceCollectionExtensions.AddControllersCore(IServiceCollection services)
at Microsoft.Extensions.DependencyInjection.MvcServiceCollectionExtensions.AddControllersWithViewsCore(IServiceCollection services)
at Microsoft.Extensions.DependencyInjection.MvcServiceCollectionExtensions.AddControllersWithViews(IServiceCollection services)
at Microsoft.Extensions.DependencyInjection.MvcServiceCollectionExtensions.AddMvc(IServiceCollection services)
at VsOnline.Reporting.Startup.ConfigureServices(IServiceCollection services) in D:\a\1\s\src\VsOnline.Reporting\Startup.cs:line 168
at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
at System.Reflection.MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.InvokeCore(Object instance, IServiceCollection services)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.<>c__DisplayClass9_0.g__Startup|0(IServiceCollection serviceCollection)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.Invoke(Object instance, IServiceCollection services)
at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.<>c__DisplayClass8_0.b__0(IServiceCollection services)
at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.UseStartup(Type startupType, HostBuilderContext context, IServiceCollection services, Object instance)
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.<>c__DisplayClass9_0.b__2(IApplicationBuilder app)
at Microsoft.AspNetCore.Server.IISIntegration.IISSetupFilter.<>c__DisplayClass4_0.b__0(IApplicationBuilder app)
at Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.b__0(IApplicationBuilder app)
at Microsoft.ApplicationInsights.AspNetCore.ApplicationInsightsStartupFilter.<>c__DisplayClass2_0.b__0(IApplicationBuilder app)
at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken)