Projects incredibly slow to open in v17.7-30+ minutes - takes <1 min in v16.1.3 for same project

I've got multiple projects with large number (hundreds) of images linked.

Somewhere around version 17.6.x or 17.7, After Effects got incredibly slow when opening projects, starting a render, or doing a Generate Content Aware Fill. For any of these items, it appears to be verifying all the files - I see hundreds of MB/sec of throughput from the 10GigE NAS (12 drive Synology) for a long, long time before the project opens, or a render begins, or similar. YES I've turned off the verify files checkbox in preferences. YES I've deleted preferences and reset preferences to make sure verify files is NOT activated. I'm not sure what else to do. Projects that open in a minute or less in v16.1.3 are taking 30 min to an hour to open on 8 and 10 core machines with 64 GB+ of RAM and 10GigE connections to the NAS. This should all be fast and it isn't.

Suggestions? Fixes? I'm working in v16.1.3 as much as I can, but the Content Aware Fill is so much better in v17.7 I need to use that, and it is costing me hours a day.

-mike