Hi Tony,
I assume you are using the index table engine, based on my test searches.
The word “pd165n” is contained in two titles, one of them is “30150-PD165N-FR-HB”. This title is indexed as “30150-PD165N-FR-HB”, “30150”, “PD165N”, “FR”, “HB”. The problem is, that the index table engine can only run queries matching the start or the end of the keywords – and in this case “PD165N-” does not match any of these, considering the criteria.
I believe the best and quickest possible resolution to this is, to simply add a keyword exception for the “-” character, by entering it here: https://i.imgur.com/phTU9OI.png
That should do the trick.