Check for burrs on the bolt and in the lower. Might be time to chase the threads with a tap and die set.do you have any other grips screws you can try?
Different grip angle or at least the inner threads inside the new grip are at a different angle causing crossthreading. Check the angles with the bolt from the top end into the grip, not from the bottom.
Run a tap through that because it looks cross threaded bad.
It has the S stripped out of it. Might be able to get a grip screw in there to straighten it out but it prolly needs a tap run through it like @dlbleak and @Snattlerake said. Looks like way too many threads have been damaged.
it has been cross threaded. if you blow up the second pic you can even see a piece of thread hanging down inside the hole. a tap should fix it and if that doesn't work you will need a helicoil.
Here’s a next step idea if the tap doesn’t work or you don’t have access to one. Take a next size drill bit and carefully clear away the damage to take advantage of what threads are left. There’s plenty there to get a hold of.