In (Options/Audio) I set playback from 'Driver' to 'Mixer' fixed this problem.
Just today I opened one of my projects and the play position indicator did not move in sync while my song was playing, but jumped to the very end while the song played correctly. So, I installed the new update in FL Studio to the new 20.8.4.2576 version. The same problem persists. I don't know if it is a Windows problem or an FL Studio glitch. The play position indicator does not track the song but jumps to the very end of the song even while the song is playing perfectly. Therefore, I have no idea where I am in the song and makes FL Studio unusable now. What a nightmare! Help!
Rick