God hates Lock-On grips
Cause 'Lock-On' type grips are usually thinner.
For example. My favorite grip is the Yeti logo grip. Nice and squishy with lots of grip. I bought a pair of Yeti Lock-Ons and they SUCKED compared to the good 'ol regular ones. The regulars felt much beefier and squishier (is that a word?!?!

).
And from the dawn of time (When I worked as a bike mech in the late '90's) 4 simple steps to perfect grips.
1. Clean bars with paper towels and rubbing alcohol (I use 90%)
2. Wash grips inside & out with dish-soap to remove mold release agent (oils)
3. Spritz the Aqua-Net™ cheap-ass hair spray onto the bars
4. Slide grips into position; rotate a couple times around bars and leave OVERNIGHT, if not for a whole day.
Perfect non-slipping regular grips.
To remove, air compressor with needle, OR Find pump bottle with thin needle-like extension and inject plain water between the grip/bar.
The Trick in all this is NO OILS! Everything, even the inside of the grips must be super clean and dry before installation.