Migrating IdentityServer4 from v3 to v4

How to fix run time errors on MVC app and API, after migrating a working IdentityServer4 solution from v3 to v4?

IdentityServer4 setup:

var builder = services.AddIdentityServer(    
   .AddInMemoryIdentityResources(Config.Ids)
   .AddInMemoryApiResources(Config.Apis)
   .AddInMemoryClients(Config.Clients)
   .AddTestUsers(TestUsers.Users);

public static IEnumerable<ApiResource> Apis =>
   new ApiResource[] 
   {
      new ApiResource("api1"),
      new ApiResource("api2")
   };

MVC client config:

new Client
   {
      ClientName = "MVC website",
      ClientId = "mvcclient",
      ClientSecrets =
      {
         new Secret("secret2".Sha256())
      },
      AllowedGrantTypes = GrantTypes.Code,
      RequireConsent = false,
      RequirePkce = true,

      RedirectUris = { "http://localhost:5002/signin-oidc" },
      PostLogoutRedirectUris = { "http://localhost:5002/signout-callback-oidc" },

      AllowedScopes = {"openid", "profile", "offline_access", "api1", "api2" },

      AllowOfflineAccess = true,
   },

MVC app OpenId Connect setup:

.AddOpenIdConnect("oidc", options =>
   {
      options.Authority = "http://localhost:5000";
      options.RequireHttpsMetadata = false;
      options.ClientId = "mvcclient";
      options.ClientSecret = "secret2";
      options.ResponseType = "code";
      options.SaveTokens = true;
      options.Scope.Add("api1");
      options.Scope.Add("api2");
      options.Scope.Add("offline_access");
      options.GetClaimsFromUserInfoEndpoint = true;
   });

Error after migration:

Sorry, there was an error : invalid_scope
Invalid scope

API setup:

services.AddAuthentication("Bearer").AddJwtBearer("Bearer",
   options =>
   {
      options.Authority = "http://localhost:5000";
      options.Audience = "api1";
      options.RequireHttpsMetadata = false;
   });

API error after migration:

401 Unauthorized