oidc-client-ts: [JsonService] getJson: Network Error (during logout)

Hello, I have recently updated from 2.0.0-rc.3 to 2.0.2 (2.0.3) and I’m noticing an issue during logout (it seems it actually started somewhere around rc4 or rc5). It looks like the /connect/endsession endpoint fails for some reason. We are using IdentityServer4 as the back-end.

Could someone please give me a hint what has changed in the way the endpoint is called by the library? It worked before in the rc3 version. Any advice will be highly appreciated.

This is what comes out of the log:

[UserManager] _signoutStart: loaded current user from storage oidc-client-ts.js:48
[UserManager] _signoutStart: setting id_token_hint in signout request oidc-client-ts.js:48
[UserManager] removeUser: begin oidc-client-ts.js:48
[UserManager] storeUser: begin oidc-client-ts.js:48
[UserManager] removing user oidc-client-ts.js:48
[WebStorageStateStore] remove('user:https://identity.server:8443:AppName'): begin oidc-client-ts.js:48
[UserManager] _signoutStart: loaded current user from storage oidc-client-ts.js:48
[UserManager] _signoutStart: setting id_token_hint in signout request oidc-client-ts.js:48
[UserManager] removeUser: begin oidc-client-ts.js:48
[UserManager] storeUser: begin oidc-client-ts.js:48
[UserManager] removing user oidc-client-ts.js:48
[WebStorageStateStore] remove('user:https://identity.server:8443:AppName'): begin oidc-client-ts.js:48
[UserManager] removeUser: user removed from storage oidc-client-ts.js:53
[UserManagerEvents] unload: canceling existing access token timers oidc-client-ts.js:48
[Timer('Access token expiring')] cancel: begin oidc-client-ts.js:48
[Timer('Access token expired')] cancel: begin oidc-client-ts.js:48
[Event('User unloaded')] raise: oidc-client-ts.js:48
[UserManager] removeUser: user removed from storage oidc-client-ts.js:53
[UserManagerEvents] unload: canceling existing access token timers oidc-client-ts.js:48
[Timer('Access token expiring')] cancel: begin oidc-client-ts.js:48
[Timer('Access token expired')] cancel: begin oidc-client-ts.js:48
[Event('User unloaded')] raise: oidc-client-ts.js:48
[UserManager] _signoutStart: user removed, creating signout request oidc-client-ts.js:48
[OidcClient] createSignoutRequest: begin oidc-client-ts.js:48
[MetadataService] _getMetadataProperty('end_session_endpoint'): begin oidc-client-ts.js:48
[MetadataService] getMetadata: begin oidc-client-ts.js:48
[MetadataService] getMetadata: getting metadata from https://identity.server:8443/.well-known/openid-configuration oidc-client-ts.js:48
[JsonService] getJson: begin oidc-client-ts.js:48
[JsonService] getJson: url: https://identity.server:8443/.well-known/openid-configuration oidc-client-ts.js:48
[UserManager] _signoutStart: user removed, creating signout request oidc-client-ts.js:48
[OidcClient] createSignoutRequest: begin oidc-client-ts.js:48
[MetadataService] _getMetadataProperty('end_session_endpoint'): begin oidc-client-ts.js:48
[MetadataService] getMetadata: begin oidc-client-ts.js:48
[MetadataService] getMetadata: getting metadata from https://identity.server:8443/.well-known/openid-configuration oidc-client-ts.js:48
[JsonService] getJson: begin oidc-client-ts.js:48
[JsonService] getJson: url: https://identity.server:8443/.well-known/openid-configuration oidc-client-ts.js:48
[JsonService] getJson: HTTP response received, status 200 oidc-client-ts.js:48
[MetadataService] getMetadata: merging remote JSON with seed metadata oidc-client-ts.js:48
[MetadataService] _getMetadataProperty('end_session_endpoint'): resolved oidc-client-ts.js:48
[OidcClient] createSignoutRequest: Received end session endpoint https://identity.server:8443/connect/endsession oidc-client-ts.js:48
[OidcClient] createSignoutRequest: Signout request has state to persist oidc-client-ts.js:48
[State] toStorageString: begin oidc-client-ts.js:48
[WebStorageStateStore] set('916ec334c503453f859932320e64bc29'): begin oidc-client-ts.js:48
[UserManager] _signoutStart: got signout request oidc-client-ts.js:48
[RedirectNavigator] navigate: begin oidc-client-ts.js:48
[JsonService] getJson: Network Error react_devtools_backend.js:3973:25
    overrideMethod react_devtools_backend.js:3973
    error oidc-client-ts.js:63
    getJson oidc-client-ts.js:473
    getMetadata oidc-client-ts.js:583
    _getMetadataProperty oidc-client-ts.js:614
    getEndSessionEndpoint oidc-client-ts.js:604
    createSignoutRequest oidc-client-ts.js:1476
    _signoutStart oidc-client-ts.js:2469
    signoutRedirect oidc-client-ts.js:2414
    _callee7$ AuthenticationService.ts:170
    Babel 10
    _callee2$ Logout.tsx:93
    Babel 10
    _callee$ Logout.tsx:52
    Babel 8
    Logout Logout.tsx:79
    React 4
[UserManager] _signoutStart: error after preparing navigator, closing navigator window oidc-client-ts.js:48
[RedirectNavigator] close: begin oidc-client-ts.js:48
Redirect signout error:  TypeError: NetworkError when attempting to fetch resource.