www.makemkv.com

are you using mkv remux or m2ts? had a few remuxes that stuttered, all m2ts have been fine though. I don't own a B9 but many others who do have no problems. you can try yusesope's tool and make a bl+el-rpu hevc then run that through mp4 muxer via profile 7. I've used both, no luck with either sadly.

Did anyone ever find a fix for the stutter problems using Grencola's tool?

I haven't been able to get a single working file with that tool, they all stutter like crazy on my LG B9.