Even if trees are tied, there can be some room for movement. Check that wind hasn’t rocked the tree enough to create a pocket in the soil around the trunk. Use your foot to firm the soil back in place and make sure there isn’t space for water to freeze and thaw around the roots and stem.
Check that nothing is rubbing against the stake or tie. Broken or abraded branches make good entry points for disease. Cut any damaged branches so the bark doesn’t tear.