Unable to move Azure App Service to another Subscription

Hello Community,

I have a App Service, that has been deployed from the marketplace (Wordpress) with a MySQL DB. I want this whole Service, App Service, App Service Plan and MY SQL DB to be moved to another Subscription. But, i always run in Problems. During the Verification Process i get this Issues:

{"code":"ResourceMoveProviderValidationFailed","message":"Resource move validation failed. Please see details. Diagnostic information: timestamp '20200213T100755Z', subscription id 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', tracking id 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx', request correlation id 'xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxx'.","details":[{"code":"ResourceMoveProviderValidationFailed","target":"Microsoft.Web/certificates","message":"{\"Code\":\"BadRequest\",\"Message\":\"Please select all the Microsoft.Web resources from 'Default-Web-WestEurope' resource group for cross-subscription migration. Also, please ensure destination resource group 'XXXX-RG' doesn't have any Microsoft.Web resources before move operation. Here is the list of resources you have to move together: XXXXXXXX-projects (Microsoft.Web/sites)\\r\\n WebApplication38953 (Microsoft.Web/sites)\\r\\n timetrackernewsfeed (Microsoft.Web/sites)\\r\\n XXXXXXXX-blog (Microsoft.Web/sites)\\r\\n XXXXXX (Microsoft.Web/sites). This resource is located in resource group 'XXXXXX_Prod', but hosted in the resource group 'Default-Web-WestEurope'. This may be a result of prior move operations. Move it back to respective hosting resource group\\r\\n Default1 (Microsoft.Web/serverFarms)\\r\\n XXXXXX-blog-Plan (Microsoft.Web/serverFarms)\\r\\n XXXXXXX-projects (Microsoft.Web/serverFarms)\\r\\n DD90514816160753107856EA67F8B067B92F04D3-WestEuropewebspace (Microsoft.Web/certificates)\\r\\n. Please check this link for more information: https://portal.azure.com/?websitesextension_ext=asd.featurePath%3Ddetectors%2FMigration#resource/subscriptions/XXXXX-xxxxx-xxxx-xxxxx-xxxxxxxxx/resourceGroups/Default-Web-WestEurope/providers/Microsoft.Web/sites/xxxxxxxxx-projects/troubleshoot\",\"Target\":null,\"Details\":[{\"Message\":\"Please select all the Microsoft.Web resources from 'Default-Web-WestEurope' resource group for cross-subscription migration. Also, please ensure destination resource group 'xxxxxxx-RG' doesn't have any Microsoft.Web resources before move operation. Here is the list of resources you have to move together: xxxxxx-projects (Microsoft.Web/sites)\\r\\n WebApplication367843 (Microsoft.Web/sites)\\r\\n xxxxxxx(Microsoft.Web/sites)\\r\\n xxxxxx-blog (Microsoft.Web/sites)\\r\\n xxxxxxx 

I also removed the Certificate and tried to move, but still not working.

Any hints or solutions for this Problem?

Thanks & Kind Regards, Peter