IOS: looks like glDeleteBuffers does not release memory

I am using OpenGL ES buffers in different places (Texture, Index, Color buffers, etc.).

When I profile my OpenGL ES code with Allocations, I see that all memory glBufferData

stored in the GL context is never freed.

It is listed in the Allocations utility allocateWCMemory

in the library GLEngine

.

Profiling was done on an iPad Mini 2 running iOS 8.3 (OpenGL ES 3.0).

After numerous uses of glBufferData (always with different buffers, only once for each buffer), no allocation has been freed by glDeleteBuffers.

glDeleteBuffers is called for all generated buffers after they are not needed.

Is there something else in GL ES 3.0 what should I do about it in order to free the buffers? What are the alternatives to glBufferData if it's a systemic GLEngine

iOS implementation issue ?