audio waveforms disappearing and reappearing

I just converted a project from a Premiere timeline to DR, then created Optimized Media in ProRes LT
Original footage is all H.264 in UHD and Premiere just cannot do it.

My timeline converted fine but after editing for a bit of time my audio waveforms started disappearing and reappearing. Most of them will be there, visible and audible. Then I go further down the timeline, and clips from the same camera have lost their waveforms - they are no longer visible or audible. Then I go further down and there are waveforms on other clips. If I open the clips w/o waveforms in the source window and play them, the waveforms appear in the source window and I can hear the audio. But not in the timeline.

I've restarted DR a couple of times and the waveforms have reappeared in some clips. Also restarted the entire system and others reappeared. But not all! So seems like an issue related to cacheing or linking to the optimized media files. Or is the computer bugging out? Its on the older side but has been doing great with DR so far.

Is this a memory issue? One one file I waited and keep clicking and then the waveforms finally reappeared. But the computer is not acting like it usually does when the memory is maxed out. Playback is mostly fine, nothing else lags, other programs run well.
All the media and cache files are on the RAID drive, in different directories - could that be the issue? Should the cache be on the computers hard drive?
Or is this the graphics card or processor?


Starting the software over and over will clearly not cut it so wondering how to actually fix this. This is a 15 minute doc short, the longest I've tried to edit on DR. Is a test as to whether I should try to do a feature, and if this is what happens 8 minutes into a timeline then DR is failing the test!

Running DR 14.2.0
Mac OS Sierra 10.12.6
Retina 5k
3.3 Ghz
8GB DDR3 memory
MS Eswon R9M395

I figured this out and want to update this in case others have the same issue. W
hat happened is that footage from an FS7 buried the audio tracks, either during the XML transfer or during the transition to optimized media. So footage that had 2 designated audio tracks with 2 mikes turned into footage with 64 tracks, and DR was reading all 64, and bringing 64 tracks onto the timeline without any obvious way to select only the 2 I wanted. I locked out all my other tracks and only had 6 audio tracks but when I brought clips in DR just added 64 more. Fun clean up.
To fix this I went manually to "clip attributes" for each clip, and set the audio input for track 1, track 2, etc to take as a source from audio 1 or audio 2. That restored everything. I could "select all" and do this as a group but it was not what I would call a streamlined workflow.
What would be nice it to be able to do this globally either during optimizing or from the media pool. Perhaps that function exists but in trying to finish my piece I didn't dig around that much yet. If there is a BMD person reading this who can shed some light that would be lovely.
Another nice thing would be to designate source audio and destination audio. I also looked a bit for that and did not find yet.