Don’t over tighten the finger bolt or you will crack the mount... just nipping it up lightly with your finger tips is enough... this will also allow you to gently adjust the cameras position if needed. Besides you may need to twist the camera in an emergency to record footage which is beyond it’s 170° viewing angle..
Don’t use any oils or greases to help stick the mount to the windscreen, this will only soften and/or perish the suction cup.
I’ve removed my G90 mount a number of times and successfully remounted it as solidly as the first time using this method...
Warm the suction cup up with a hairdryer, this will allow it to return almost to its original flat shape and will make the suction cup malleable allowing you to form it into a slightly convex shape.
Once done allow the suction cup to cool and it should retain nearly all of its new shape.
Clean the windscreen and suction cup with pure vinegar (best window cleaner in the world) and give it a few moment to dry.
Warm the windscreen with the hairdryer and whilst the windscreen is still warm mount it back onto the windscreen.
If done correctly it will stick solidly back onto the windscreen with no chance of it falling off.
You can tell if you’ve been successful as you should see a nice thick dark circle on the windscreen when viewing the mounts suction cup from the outside of the car.
Mine goes back on so well I’m afraid of breaking the mount as the suction leaver is quite stiff to turn.
I’ve heated the windscreen with a hairdryer until it’s very hot (like a hot summers day) and it hasn’t budged.
It’s only been -5 outside so far this year, but it’s still stuck to the windscreen as solid as a rock.
I hope someone finds this info useful