(iOS) PvZ1 - serious lagging after since latest v3.1.0 update

I have been playing PvZ1 on iOS for two weeks or so and a couple of days ago my game started lagging crazily.

At that point I have completed adventure mode and was playing extras, so I thought to myself...well, the game is old, maybe it has a problem, so I reinstalled the game (I didn't know there is no progress sync, so I lost all my progress), started playing again and after two levels or so, again, the same problem.
Phone (I am running iP12, latest stable iOS version) is heating up a lot and I guess I am getting ~10fps, however whether system, other apps or games, only PvZ has the same issue and considering there was this update a week ago I suspect that is a culprit.

I thought I will report a bug, however that form at help.ea.com would give me answers HQ as the only contact option.