Optimized Code in Release build won't render with F#

[ghost]

Triangles are not rendered in Release build. Clear color is rendered though, and even the audio still works.

I tried to force x86, and x64, but only disabling 'Optimize code' renders the triangles again. I tried DotNet 4.5, 4.7, and even 4.7.1, but no difference. Tried F# version 4.0.0.1, and the latest 4.5.1. SharpDX 3 also doesn't seem to change anything.

So, needless to say that this makes it impossible to make a game with F#. :/