I'm also seeing this issue. Everything is correctly reported as up-to-date when using Composer but on your Drupal site go to:
[yoursite.com]/admin/reports/updates and it says there's an update available for Dropdown_Language from version 4.0.3 to 4.1.0 but also lists it as incompatible, since it is not compatible with Drupal 10.
We would expect it to show that no update is available since it's not compatible with our version of Drupal. It also means that if you've got Email Notifications set up you get daily emails stating updates are available when there's not.
I hope this information helps you find a solution to this issue. I have also attached a screenshot of the issue.