TG 20107 is school buses
TG 2610 is LE unknown location
Probably, no one has submitted 20107 to the database, or the DB admin with the submission has not yet had time to process it.
TGID 2610 is Gregg County SO Dispatch 1. If you're hearing them at your location, then one of their units is out of their home county, and at a location near you. Their radio affiliated with a site within range of you, like Van Zandt or Kaufman, so that TGID is being carried there as well as "back home".
TG 3690 shows as unknown in the sds, but is listed as Smith County SO in the database.
What do you mean, it is "unknown in the SDS"? It's in the Sentinel database, and would have been loaded to your scanner the last time you did an update to your Favorites list. Have you updated your list recently?