There are way too many issues with the game. Firstly, the load times for menus, worlds And the game itself are extremely long. When trying to play with other people on different platforms or on servers I'll get disconnected a few minutes in. The game will often start having serious frame rate issues at random and the music will stutter. The game is just broken. Please fix these issues ASAP.
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Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-41479.
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After the 1.9 Update, The Lag is insane. It makes the game unplayable and eventually makes you feel a bit sick.