How do I prevent my radar from getting stuck?

Recently, there are times when I will go to lock a plane and the radar will go into that square/rectangle that it normally does when it attempts to lock a target. However, it will fail to lock the target then get stuck in that ‘attempting to lock’ mode for a while, maybe 5 sec min sometimes 10. This really messes with my game play as it means that I do not have enough time to try to another lock before their plane gets too close for a aim7 attempt.
Is there something I am doing that causes this and if so, how do I prevent it?

This is a bug afaik, it happens to me but not often (I mainly use ACM mode when I have it), if it happens there is nothing you can do