Items identified as 'First Available' but not visible


Hello Folks,
I would appreciate any guidance on the following ‘missing items’ puzzle. I have attached a screenshot to hopefully clarify my query. On selection of a particular tag (“Plan”), along with filtering the possible results using the ‘First Available ‘filter’’, I note that OF informs me that there are ‘20 first available’ with this tag. However, the 20 items are not ‘surfaced’ from the database.
Any insight or help on this issue would be appreciated.

/Users/stephenedgar/Pictures/Photos Library.photoslibrary/resources/proxies/derivatives/25/00/256e/UNADJUSTEDNONRAW_thumb_256e.jpg