Render bug on Mali-T760

I've found render bug on a multiple RK3288 devices with Mali-T760 GPUs. The devices are on driver versions 11 and 14, but both have the same problem. Here is the version string for one of the devices: OpenGL ES 3.2 v1.r11p0-00rel0

The problem appears when mapping buffers to uniforms and calling glFlush multiple times per frame. I have a simple Android project that reproduces the problem here. The image below on the left is the output on my Mali devices, the image on the right is what you see when you remove the glFlush command or run the original code on a different device such as a Pixel 1.

Broken Correct