The system should be set up as a
"P25 Trunk" period.
That covers both P25 Ph1 & Ph2 systems. If you have it programed as anything else [ex. X2 TDMA], There's bound to be problems that are undesirable. And, If encryption is in use, the scanner will ignore those calls and continue scanning for a clear call. (Provided that is; You're actually within range of a sites' control channel.) DMR (Yeah or Nay) would have zero bearing on a P25 system, Also the squelch should be set at 2, no higher, for best results. (Sometimes a 0 or 1 Setting is required, but that can create some obvious issues if conventional items are being actively scanned with a CSQ/Search audio option)
I don't see a site listed specifically for the county you mentioned. What site(s) are you trying to scan? Do you see any indication on the screen
"Data" that indicates a control channel being received. You need to be seeing that before any traffic would be picked up.
Scanner Frequencies and Radio Frequency Reference for Luquillo County, Puerto Rico (PR)
www.radioreference.com
Polica de Puerto Rico (PRPD) - Red de Radio Interoperabilidad Trunking System Profile
www.radioreference.com
According to the DB page it's P25 PH1 and Encryption is not indicated (P25 PH1 De/DE P25 PH2 Te/TE) but that could be just a lack of info, encryption
may be in use (law enforcement going 100% E is unfortunately the norm these days) and the DB page is based on user submissions, If there's been a change, it hasn't been submitted/updated.
You can view the locations of the known sites here:
The most complete database of radio communications data
www.radioreference.com
Are you close to any? I'd try finding the closest site and Hold on that site, If you are scanning every possible site on the system this would delay/miss hearing any traffic on the site(s) in range.
These are the two sites I'd concentrate on trying to pick up, based on your location as listed.
Polica de Puerto Rico (PRPD) - Red de Radio Interoperabilidad Site: Yunque Mountain Details
www.radioreference.com
Polica de Puerto Rico (PRPD) - Red de Radio Interoperabilidad Site: Cerro Los Machos Details
www.radioreference.com
I'd create an FL in Sentinel and avoid all the sites except those two for starters. Also the option ID: Search should be On so any unknown TGID's that are active would be received. Increasing the systems Hold Time can improve your chances, You can experiment going from 0 to 255 sec.
Hope at least some of that makes sense and provides a small bit of help.