First, make sure you have a clean print surface use some isopropyl alcohol and wipe it down. You can also pull the print bed out and wash it in some warm soapy water, just make sure you don’t touch it with your greasy finger prints.
If this still doesn’t work, apply some hair spray to the build plate while cool, not much just a lite layer. This will not only help the print stick to the plate, but will act as a buffer for other materials that have a tendency to stick TOO well like PETG