December 2016 - last edited December 2016
I have discovered a way to do this on an android device the only problem is that it is kind of broken but will still allow you to keep your data what you have to do is go to /sdcard/android/data/com.eagame.pvz2_n/files/no_backup and in there there is a file called pp.dat that is the save file for the game what you have to do is copy that and put it on the new device the only thing is that you can only load this offline, once the game is loaded you can go online but every time you load the game you must be offline if you load it online it acts as a fresh install of the game and deletes all game data, and the only way to get your data back is to put the file back into the folder it is recommended that you make a backup when you are done playing that way your progress is saved it will save it for you but you will lose it if you load the game on accident, even if you load it online and it says create a user profile and try to quit it will still not fix the issue. If there is any other way you know please be sure to share this is the only way i have found but only works offline.
It is possible to move your game to a different device - I've done it in the past. In fact the device I was originally playing on just seems to have died (Nexus 7 2014). However... I can't move the game to my new cell phone (Moto G4 unlocked no sim card). When I look at the acheivements I can see MINE, but the game won't let me play MY game. All I can do is start a new one.
I'm still experimenting. I'll get back to you if and when I find a solution.
I had this same problem... like the servers were refusing to sync...
Just copy the save data manually to the new device... it works for sure:
In the past, I have always been able to login with Google+, tap on my profile name, and get all of my progress. I have had this game over like 4-5 phones. Now, I get nothing. My achievements are all there, but all my levels, plants, coins, gems etc are GONE. Has EA/Popcap helped anyone with this yet? Are we all screwed?