It could be a caching issue. WordPress may show older data 1-2 times after you add edit restrictions to a user or role, especially when you test it (before and after changing available posts list) at the same browser. Can you repeat this in a different browsers: login at one browser as admin, and as a test user at another browser.

Edit access restrictions works for multiple roles assigned to the same user this way:
URE takes an access model (Allow or Block) from the 1st role and add to it access conditions from other roles with the same access model only. For example: User has 3 roles. 1st role: Allow, 2nd role: Block, 3rd role: Allow. Access conditions will be applied from the 1st and 3rd roles only.