In your post you noted the updates are the cause. You'll have to go back to what worked or wait for the game maker to fix it.
https://www.reddit.com/r/PUBGMobile/comments/99g1eu/pubg_performance_on_different_phones/ tells us we have settings like Utlra, Balanced and more. I'm finding folk that go for the max and forget they can pull back on settings.
Can some one please explain why the recent updates of pubg has made it more laggy and choppy. I have Redmi Note 4 (4gb RAM) which has more than enough hardware specification to run pubg smoothly, still recent updates has made it very difficult to play peacefully. If anyone knows how to fix this please let everyone know by commenting down.