Check the suggestions attached below if you are experiencing such issues:

1. Quitting all applications that are currently progressing to make extra space for your memory.

2. Check your network connection.

＊ Network connection will be unstable in crowded or isolated areas.

＊ It will also be unstable upon using Wi-Fi or Hotspots that are used by multiple people.

3. Adjust your Game Graphic Settings

 ＊ Utilize graphic settings to the preferred settings for your device through Menu > Setting > Environment > Graphic. Examples: Texture Quality, Shadow Quality,  Anti-aliasing quality, and further options.