The Smart Preview Status column in the Library Filter bar's Metadata browser shows wrong counts. To reproduce:
1. Start with a catalog containing many photos.
2. In All Photographs, do Expand All Stacks, select all the photos, and do Library > Previews > Discard Smart Previews.
3. Select the first 10 photos and do Library > Previews > Build Smart Previews.
4. Create a smart collection with the criterion "Has Smart Preview is true". Observe that the smart collection shows a count of 10.
5. Open the Metadata browser with the single column Smart Preview Status and select Has Smart Preview.
6. Observe that the count for the line Has Smart Preview usually is much less than 10, but the number of photos displayed in Grid view is always the correct 10.
See here for the original report:
https://www.lightroomqueen.com/community/threads/wrong-photo-counts-in-metadata-filter.42872/
Tested on LR 10.2 / Mac OS 11.1 and 10.2 / Windows 10. Since it's occurred on three different machines, I haven't tried resetting preferences.
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