Why won't Finder return "partial" search results (i.e. if I type in characters I know my file names have, why doesn't it display them)?

Not sure how to phrase this better, but...

I'm working on an iMac with OS Catalina 10.15, and I switched about two years ago from a 2009 Mac. A feature I remember Finder used to have was a "filtered" search option, like... let's say on my Desktop I have 12 files, and they all end in '-ABCDE'. I could type in '-ABCDE' in Finder, and it would populate a list of just the files with those exact six characters, so I could move them or copy them all at once.

Now on my new iMac, I'm trying to do the same thing. I work in art/production and we use common character strings to indicate certain files. For example, our proof files always end in '-P,' final production files end in '-XXXXX' (job number). So it's endlessly frustrating when I have just saved out tons and tons of files which all share a common string of characters, but Finder doesn't seem to ever find them, even though I just created them, and know they all share common characters I want to select them all by. Sometimes I want to just grab the final files to put on another computer, or sometimes I just want to grab the proof files to send to someone. But right now it seems I have to just manually go through my folders and select, by hand, each file, because I can't 'collect' them through Finder anymore.

Any thoughts? Is it some setting I'm missing?