Hi Frans,
In the change action of your AfterCreate microflow, did you check the 'Refresh in client' option? If so, the client refreshes immediately after adding a new row, causing this newly added row to appear on a different location (depending on the sort order). You do not need to use 'Refresh in client' in an after create microflow. The microflow is executed before the object is sent to the client, which means that the client will already see these changes.
Let me know if this solves your problem.