I tried playing with this, but could not get the radio id alert to override the talk group alert.
example I have the TG alert to show blue LED, but I wanted a radio id that uses that TG to flash RED. I would see the radio id text that I assigned, but the LED was blue for the TG
Is the feature turned on in the Advanced Settings?
Press PGM
Press FUNC
Press F3 (GLOB)
Press FUNC
Press Down Arrow (Moves you to the bottom of the menu)
Press Up Arrow 3 times (You should be at the RadioIDAlert Setting.
Set that to Yes by using the Right or left arrow if it isn't already.
Press F1 (Save)
Press Scan
See if that resolves it. If you're using software, that option should be available there as well to be set.
Edit: Note also that IIRC, this will only work while in Scan Mode, not in Manual or Pause mode.
Mike