Cannot change datasource from CRM Online to CRM On Premise ODATA connection

I can connect OK to Dynamics 365 (CRM) Online, which adds an ODATA source. I can also connect OK to a Dynamics 365 on premise tenant, which also adds an ODATA source. But I cannot change an existing D365 Online data source to an On premise one - not allowed. However, I can edit each individual query to change the URL to point to the on premise data source and it works just fine. You should allow us to change the url to an on premise ODATA source the same way you can change to other online instances.