This is working as designed.
1) So it was designed to use unnecessary CPU cycles to re-create thumbnails every time one opens a project ?
2) That means PPRO is a relic - belonging back in the days when a 500 MB hard disk was considered large.
IF this is REALLY a design... It is about the most flawed design I have ever seen in any app !
Thanks for chiming in though
2. If you say so.
(I'm not a fan of this either. I see the same flaws in the Media Browser).