Teensy 3.2 is supposed to be a direct pin compatible replacement for the Teensy 3.1 so the wiring for the 3.2 should be the same.
The library was fully tested on a Teensy 3.0 and others have used it on a Teensy 3.1 so the the Teensy 3.2 should work.
That said I've not ever tested it on a Teensy 3.1/3.2 myself so there might be an issue.
Do not guess on how to wire it up as incorrect wiring can damage the glcd or the Teensy board.
Consult the included HTML documentation for how to wire it up.
The openGLCD project page has information about the documentation included in the library.
If you have already done that and are using the documented wiring, then post back with how you have everything wired up and show a photo of your teensy, pot, and glcd with all the wires are visible so we can check the wiring.
It is wired up according to the pin mapping in Arduino pin to KS0108 Pin Function mapping Table down in the [Wiring]->[KS0108 Family] section of the documentation.
In that table you will use the mappings for the line labled: Teensy 3.0/3.1/LC
There is another table on that page, KS0108 Pin Function Table that explains the ks0108 pins and how to wire up the contrast pot.
In order to wire it up, You must have the datasheet for your exact ks0108 module since different manufacturers modules use different pin numbers for the module functions/signals.
Once you have the datasheet, you will use the two tables to see how to wire it up accordingly.
you will use the mapping table to see which teensy pin is wired to which glcd module function/signal.
and then use the datasheet to see which glcd module pin number is used for that glcd module function/signal.
For example Teensy Arduino pin 7 is connected to the glcd module EN function/signal. You then look at the datasheet to see what pin number on the GLCD module is used for the EN signal.