Spend the extra couple $s to get well sourced products.
For the LG G6, chuck any adhesive for the rear glass provided in the garbage. It'll be too thick, use ifixit Tesa 61395 tape to make yer own seal.
The fingerprint sensor is very sensitive to these small clearances. I put a piece of Tesa 61395 between the plastic lense cover and contact plate for sensor.
Now I've got a great seal and perfectly working sensor. Thanks ifixit!