I think that's a G5 limitation if you can't move anything at all (a weird one, though, if that's what they chose). Yes, both Samsung and LG decided against supporting 'Adoptable Storage' for SD Cards in their Marshmallow devices, BUT at least in Samsung phones you can still use the App move like in Lollipop or KitKat (app main file still resides in internal memory, only a part of the app is moved, and each app developer decides which parts can be moved, if any; updating apps moves them back to internal memory first).
So, to do this, first check that the app you want to move supports moving to SD Card. Then, in your Application Manager, find the app, tap STORAGE, and if you have the option to move to SD card, the option to CHANGE storage locations will show up. If it doesn't show up, either LG has decided not to implement App2SD in their ROMs or the app you want to move doesn't support it.