Rendered Timeline Not Saving

Does anyone have a fix for the issue that rendered timelines aren't saving In Premiere Pro?

I'm using the latest version of Premiere. The projects + media files are stored on one external thunderbolt drive, and the renders (cache media) are stored on another external thunderbolt RAID. These drives are always connected when the machine is on -- but I don't leave the workstation permanently on.

One user suggested making a blank sequence and, before saving and closing, having only that blank sequence open. This actually does *almost* work. Renders are saved *if* they don't have a text layer above them. Nothing with a text layer is saved.

Buying separate drives for cache media files is widely recommended within the industry. That Premiere "forgets" about rendered files on these drives everytime I open the progem is trapping me in a kind of frustrating Groundhog Day. I'm editing a 3-hour documentary feature.