Change the O-ring. I have the same exact one (V1) and ordered extra O-rings for just that reason. Mine has never leaked.
During maintenance I take mine apart, wash everything with hot water and dish soap, rinse with distilled water, dry and put it all back together. When I replace the O-ring, I coat it with a tiny bit of vaseline then slap it all back together. This prevents the O-ring from drying out and shrinking causing the locking ring from leaking right from the pic.