Audio issues on Playback effecting single track

Hi all, first time posting here.

I have encountered a small issue when using Auditions.
I currently run and edit a small podcast, we use a Focusrite Scarlet 18i20 2nd Gen and currently use 4 professional quality mics (looking to go up to 6). I use the standard set-up of running each mic through auditions, recording onto seperate tracks.

The issue I have encountered is that, when I came to edit the next episode (recorded weeks ago), there was no audio on Track 1 on the multitrack. The cursor was moving over clearly visible waveforms, and the metre input signal was moving as if there was playback.

I checked the audio hardware and mapping, as well as on my device (running windows 10). Moving the audio down to Track 5 gave me perfect playback, and when I moved audio from Track 2 onto Track 1, there was no playback. So it looks like I have a playback error on Track 1. I had used part of this same recording Yesterday, and it played back fine on Track 1 then. Re-starting the software and device didn't change anything.

Any ideas? Is this a common error?