This is often a shader cache issue. Try clearing the shader_cache folder within your data packet directory.
Ultimate Guide: Setting Up Egg NS Emulator and Data Packets on Android egg ns emulator data packet download
To set up the on Android, you must download and configure the Switch Droid data packet (sometimes called the "Switch git" or "runtime environment"). This packet contains essential system data required for the emulator to function. 1. Download Required Files This is often a shader cache issue