Since you are using direct page URL's and user has access, its hard to prevent this behavior through URL navigation.
However, I assume you do have a microflow as role based home page, to define the 1st & second login. If this is correct, I would solve it using the events widget.
- Put the events widget on the page for second login
- Create a microflow which will execute the same logic as login.
- Extract the logic which defines 1st or second login from home page microflow
- Use this sub microflow in the new microflow.
- When 1st login, open 1st page
- When 2nd or higher login, do nothing
- DO NOT REUSE THE HOME PAGE MICROFLOW DIRECTLY! this will cause infinite loop when accessing app 2nd time
- Trigger this microflow using the events widget directly when accessing the page.