Smart Albums are seriously broken

Windows 10 Professional (x64) Version 2004 (build 19041.685)

4.00 gh AMD FX -8350 Eight-Core, 32gb ram

3 ssd drives, 1T, 4T, 8T

CO v21, Catalog with 110,000 images - acceptable speed.

I have relied on smart albums for my business and livelihood since CO v9 and they have worked reasonably well until V20.1 when I started to notice problems.  I went to find an image for a client that I had recently tagged and starred and it was not in the smart album.  I eventually found it and it was starred and color tagged correctly. I didn't have time until recently to test the smart albums and after upgrading to v21 and some available time for testing I realized there is a very serious problem.

I use a fairly large catalog as it fits my business workflow and have created a number of relatively simple smart albums primarily using date-year, color tag, star ratings and keywords and several with more complex search criteria. They worked and I thought I could rely on them.

To illustrate the issue I will use just one of my smart album search criteria  - match=all, date-year is on 2019, color tag=green, star rating = 5. This smart album has normally found 111 images and only recently I questioned that number.  I added the green color tag and 5 star rating to 5 more images from one of my shoots in 2019.  When I went to find them in the above smart album they were not there.  I made sure that there were no active filters or searches in the browser or filters. I closed CO and relaunched - no difference.  I then opened an advanced search in the filter dialogue with identical criteria, set up exactly the same way and I got 139 images including the 5 I had just tagged as above.  I now knew there was a problem.

With one of these 111 images from the original smart album search I changed the star rating to 4 and it of course disappeared from the collection of images.  Unfortunately it was not found in the smart album that was for 4 star, green color tag and 2019 year.  When I did the advanced search from the filter panel for exactly the same 4 star criteria it was found along with a number more images than the smart album showed.

I then changed the stars back to 5 from 4 on that same image and checked the 5 star smart album again - it was not displayed and then did the same criteria advanced search in the filter panel and it was displayed.

I went through all 40 of my smart albums and the same type of thing was happening with all of them - they had all worked perfectly prior to v20.1 upgrade. Not only did I find the same issues with most of my current smart albums but if I created new smart albums identical to the current ones the new ones either found NOTHING or a lot less images than were in the current smart albums and they took forever to find the images - anywhere from a couple of minutes to over an hour.

I have verified my catalog several times, uninstalled and reinstalled CO, read everything I could find in the community forums and help and did a fresh install of Windows 10 Pro about 1 month ago- all to no avail. 

I cannot afford the time to do an advanced search every time I need to find my images that should be in the smart albums. I definitely do not want to revert back to PS/Bridge or LR/PS, however, time and lost sales affect my cash flow.

I am reaching out to the community for help. Is there something obvious that I am missing or something I might try to fix this problem? 

I have previously submitted tickets to tech support on this and another issue about 6 weeks ago with NO response on this issue and  a curt "It's a known issue " on my request about taking 21 minutes to open the "All Images" collection.

I have resubmitted this request today in hopes that I receive an answer or even better some help.

Thanks for any advice or help.

Bob