#2
I ran into similar problems years ago. A while back I made a video addressing this very issue. You can check out the video in this link. 



It's a pretty complicated issue but this should get you started. Hit me up if you have any questions. 

Good Luck!
#3
As well as ensuring you use a good technique, try experimenting with different guitars.

I used to have issues like this occasionally, but not all the time.  I eventually realised the times I didn't have a problem were when I was using a a Gibson with a 50s profile neck which is thicker than many other guitars.  Since then I got rid of my other guitars and exclusively use that profile neck and have never had a problem since.
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