It is an issue that I see more often (especially on social media). For me personally, it is certainly an issue and I fully understand what you encounter
First of all, you can follow the guide Denon wrote in the Knowledge base: https://www.denondj.com/kb/denon-dj-tips-prime-4-search-function
Then, if it doesn’t help you can like the original post of this request to increase the chance that it will appear on the development roadmap : Substantial improvements to Library Search performance (the Updating thing) / Faster search larger libraries
It is a problem that some users will never worry about, and others will be very annoyed. For me personally, the search speed of larger collections is the biggest annoyance of the Prime 4. Wrote on the mentioned treat above before:
I know there are ways to increase the search speed and I have a good hope somewhere that someday something will be done with this matter, but I honestly don’t think it will be soon. Of course I can be wrong, I cannot look into the schedule of development 