Hi8 audio gets progressively worse during playback, fixes itself after turning off and replaying later

Hey, I'm using a ccd-tr808e to try and capture some family hi8 tapes onto a computer and I'm running into an issue where the sound quality is near perfect when starting playback but it gets extremely distorted over the course of time, until ~40 minutes into the tape it's practically white noise. If I leave the camcorder be and then play the same section of the tape again, the sound is perfectly clean. Any ideas why this could be?