It looks like many people have opened tickets with the in-app support team. I have also done that, and they responded with “the team is aware of this problem and working on it!”
So, if the team is aware of this problem and working on it, please open an official post inside the Known Issues section here. Where is the official acknowledgement?
As per our records, we can see that you have a device running on a CPU that is lower than Snapdragon 855.
Keep in mind, that while you may still play the game on your device, there could be issues that affect your gameplay. In such cases, we won’t be able to provide additional support.
If you continue to experience gameplay issues even at the low Graphics Quality Settings, please consider playing on a different device. You can learn about our device requirements here.
In case the device meets the requirements and you experience any issues, you can contact us through in-app support or here, and we’ll investigate.
The problem is more related to the Unity engine that is used for this game. I have a MediaTek P90 SOC and I have to put it on middle graphics for no stuttering. They moved also to a different version of the engine.
I wanted to add extra information for the devs and users. The forum is Japanese and English. I use a translator. The SOC’s that you have in your smartphones are really powerful even more than my Mediatek SOC. More related to the game engine here Unity engine.