The mod said the issue is currently being investigated into
FIFA Mobile's "Seasoned Athlete Gullit milestone said to FUT 22 Coins be not completed even after unlocking the 'Rooney' fix. The event was paired with Gullit Event, which consists of nine milestones that are yet to be accomplished.
And upon the completion of all milestones that you have reached, you'll be eligible to obtain the title of Prime Icon Gullit at a place that is of your choice.These nine milestones are: Academy Graduate, Goal-Iath, Seasoned Athlete FIFA Masters, League Legend, Rising Star, Legendary Career, Triple Digits and Management Material.
There is one milestone however that can be quite a pain for those who are trying to complete the task. It's clear that this particular milestone doesn't become complete after the unlocking of Seasons Legend player "Rooney". And no amounts of restarts or clearing the app's data and re-installs seem to help.
This is a huge cause of bother for players, especially for those that have already completed all other eight milestones only to be held back by an incomplete Seasoned Athlete.Some now even believe that Rooney is one of those players that doesn't count towards Gullit Milestones.Fortunately, Rooney does count, and Seasoned Athlete isn't getting marked as complete upon unlocking him as there indeed is a bug in FIFA Mobile.
It's pretty clear from an official acknowledgment by a Community Manager on buy FIFA 22 Coins the EA forums. The mod said the issue is currently being investigated into.Therefore should everything go well then the FIFA Mobile Gullit glitch will eventually be resolved with an update that fixes bugs or via the server-side solution. In the meantime, you'll have to sit back and watch.