"bad healthcheck status" external document server

Hi,

i have the following situation:

I have a nextcloud installtion on a tinkerboard with dietpi(debian). I installed the the only-Office app. The connection to the Demo ONLYOFFICE Document Server works fine.

I have another nextcloud instance on a webhostet server. There is the Document Server and the only-Office app installed. Locally on this server only office works fine.

When I try to connect to the webhosted document server I got on the tinkerboard the error Message:
bad healthcheck status.

In the log is written:
Error onlyoffice Exception: Bad healthcheck status

    /var/www/nextcloud/apps/onlyoffice/controller/settingscontroller.php - line 170:

    OCA\Onlyoffice\Controller\SettingsController->checkDocServiceUrl()

    /var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 170:

    OCA\Onlyoffice\Controller\SettingsController->SaveAddress("https://clo ... /", "", "", "", false)

    /var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 99:

    OC\AppFramework\Http\Dispatcher->executeController(OCA\Onlyoffi ... {}, "saveAddress")

    /var/www/nextcloud/lib/private/AppFramework/App.php - line 125:

    OC\AppFramework\Http\Dispatcher->dispatch(OCA\Onlyoffi ... {}, "saveAddress")

    /var/www/nextcloud/lib/private/AppFramework/Routing/RouteActionHandler.php - line 47:

    OC\AppFramework\App::main("SettingsController", "saveAddress", OC\AppFramew ... {}, { _route: "o ... "})

    <<closure>>

    OC\AppFramework\Routing\RouteActionHandler->__invoke({ _route: "o ... "})

    /var/www/nextcloud/lib/private/Route/Router.php - line 299:

    call_user_func(OC\AppFramew ... {}, { _route: "o ... "})

    /var/www/nextcloud/lib/base.php - line 1008:

    OC\Route\Router->match("/apps/onlyo ... s")

    /var/www/nextcloud/index.php - line 38:

    OC::handleRequest()

Has someone an idea how to fix this?

Thx in advanced for your help!