No Scanner can Trunk-Track a Passport LTR
The only option is to program in all the known Frequencies and listen in conventional mode, you just won't know what TG is being used.
Also, some of the newer NGrid LTR are using Part 22 Paging channels and even tho your scanner may show/handle 25 Khz and 12.5 Khz channels, many of these are now using 6.25 Khz channels spacing.
You might want to review exactly what Freqs from both the RRDB and the SNE Wiki's
you have programmed in....
I have the Grids' LTR system programmed for some time. I watched a troubleman work a wire down today. They was plenty of Northern RI communications. Any thoughts on regaining the ability to listen to the Grid??