Audio Randomly Not Playing Back On Some Multicam Clips From a Certain Point On

I'm having an issue in a multi-cam sequence where audio randomly won't playback in the timeline for certain cameras. The waveforms are visible in the timeline, the volume on the clips are up, the track isn't muted, the sliders are up for the track, and there's no audio effects or anything like that inserted anywhere. It happens completely at random in the middle of cutting up a multi-cam sequence. Sometimes it affects the entire camera, other times the beginning of the camera plays back but at a certain point the audio cuts out and you can't hear audio from then on for that camera but you can for other cameras.

Here's my detailed project setup:

1. Created 5 sequences each containing multiple audio tracks, multiple layers of 1080p clips with some cropping, and overlay graphics.

2. Made sub sequences of those sequences so the audio will be contained in 1 event when placed on a timeline.

3. Then used those sequences as the cameras for a 5 camera multi-camera sequence.

It's worth noting that the footage used all happens to be of varying frame rates (60fps, 59.94, and 29.97) and some are mp4 while others are .MOV. It's all placed in the timeline as is without interpreting the clips because I need them at normal speed, but all of the sequences are set to 59.94. Also, I made 720p Cinemform proxies for all clips to ensure faster editing. I've done this exact procedure with one other project before and it worked relatively well so this isn't my first time trying this, the only difference is for that project all of the clips were 59.94 fps.

The audio for the individual sequences as well as the multi-cam source sequence plays back fine, it only affects the audio from the target sequence that I'm editing in. Also, I tried exporting an area of the timeline that contained clips with the audio playback issue and the audio was there on the exported clip, so this is only happening for preview in the timeline.

Specs:

Latest version of Premiere Pro CC 2019

Fully updated Windows 10 64 bit

Intel i9-7940X

64GB DDR4 RAM

NVIDIA Titan RTX with the latest studio drivers

OS and application on a Samsung 960 Pro M.2 drive

All media files are accessed from a separate 960 Pro M.2 drive

RME Fireface UFX+ (set as the ASIO audio device)

This was happening nonstop yesterday on this project that I'm currently working on and I've had a strange experience finding workarounds that eventually stop working:

1. At first it only happened for one camera and after some messing around I was able the get the audio back for it simply by alt+clicking one part of the affected audio then copy and pasting that to a different spot in the timeline. For some reason not only did the audio for the pasted clip work but the audio for the entire original clip starting playing back again as well, so I would just deleted the pasted one and move on. This workaround worked a couple times.

2. Eventually it happened again except 2 cameras were affected and this time my first workaround was no longer fixing the issue. After some messing around I found a new workaround where I pressed ctrl+a to "select all" in the timeline, and then copy and pasted that into a new empty sequence that I made. Again, after doing this the audio for the new sequence played back and the audio for the original sequence was somehow fixed as well, so I just deleted the new one and continued editing. I think this workaround worked twice if I remember right.

This is where I am now:

After some more editing it happened again, this time there's only some audio at the beginning of one of the cameras and the rest of the cameras have no audio playback anywhere at all. I tried the workarounds from both 1 and 2 multiple times. 1 doesn't work at all, and 2 sort of works if I only copy and paste small sections at a time into the new sequence, but if I paste a section that's too big there will be no audio for that paste. Also, this time when I successfully paste something into a new sequence that brings back the audio, the audio from the original sequence still doesn't play back unlike my experience with the first 2 workarounds before this. I've considered trying to just paste small sections at a time into the new sequence, making sure it plays back, and then moving on to the next small section until I have all of the edits back with audio in the new sequence. The problem is, that will take a really long time and it will be easy to really mess something up because I have a LOT of cuts, not to mention there's a good chance it will stop working at some point and be a huge waste of time.

Some other things I've tried include opening and closing the project, restarting my computer, copying the project inside a new project, opening project manager and copying everything over to a different SSD drive (I tried this twice, once using the source clips and a second time setting "consolidate and transcode" and making everything Cinceform .mov files), muting / un-muting / soloing / un-soloing tracks, and of course I messed around with settings in preferences. Nothing seems to be working this time.

This is extremely frustrating because I am really far into this edit and I'm on a tight deadline so I'm running out of options and sort of desperate for a workaround that will allow me to finish this project! I'm honestly having a BUNCH of other issues with crashing and other weird bugs in Premiere as well, but those generally resolve themselves after restarting Premiere or using one of the many workarounds I have come up with. This audio playback issue though, is the first time that I'm literally stuck and have no idea how to get back to editing. Please help!

EDIT: I read it back and saw a bunch of typos and wanted to re-organize it to make it easier to follow.