Issues creating workspaces if you selected all subscription in Azure Portal filter
if you are creating workspace and you selected all subscription in Azure Portal filter. the worskpace will be created in the first one and this could be confused. this is not in the official documentation.
I assume that the scenario you describe started when selection Log Analytics on the on the left navigation, selected multiple subscriptions in the filter and then clicked ‘+’ to create a new workspace. In this case, a new page is opened for workspace creation, with subscription drop pre-populated with the first subscription in the filter, but you can change that selection per your choosing. This behavior is quite common across azure and also used in this experience.