Audio Problem with Adobe Premiere Pro 2019 (Audio is Quiet and Muffled)

Hi! For the past two days I have had an audio problem with Adobe Premiere Pro 2019: the audio is unusually quiet and sounds muffled. This happens with all of my audio track(s) in all of my Premiere Pro -saves. There isn't anything wrong with the audio track(s), because they sound fine when the video is exported from Premiere Pro or when the audio track(s) is viewed in Adobe Audition or in any other program. The problem is only inside Premiere Pro and I don't know how to fix it. Both Audio Meters and Audio Gain for the track(s) show the correct numbers, but the actual audio that I hear, doesn't match to those numbers. The audio has been working fine in the past and I have not changed any settings - only thing that I have done, is to update the program, but this problem started before I updated the program.