The "Subscriptions" widget actually does not display all workspaces (or pages), but those you have subscribed to.
For example, the reason why you don't see all the workspaces of which you are a member in the widget is probably because you haven't subscribed to them. This also means that you will not be notified of new posts and activities in these workspaces.
To check this, go to the workspace that is not displayed in the widget and check if the bell at the bottom left (under "Options") is blue or white.
If you have subscribed to a workspace, the bell is blue and it looks like this:
For example, the reason why you don't see all the workspaces of which you are a member in the widget is probably because you haven't subscribed to them. This also means that you will not be notified of new posts and activities in these workspaces.
To check this, go to the workspace that is not displayed in the widget and check if the bell at the bottom left (under "Options") is blue or white.
If you have subscribed to a workspace, the bell is blue and it looks like this:
