Problem with graphicsExample on Raspberry Pi, maybe alpha blending related

I just installed OF v0.10.1 on a new Raspberry Pi 3 A+

The graphics example has a problem that seems to be related to alpha blending. If you run the example you will notice some of the rectangles missing, e.g. the 200 random color size rectangles. They flash up the very first frame then disappear.

If I comment out the one call to ofDisableAlphaBlending(), the example runs normally.

So it looks like enabling and disabling of alpha blending is causing some issue… anyone else notice this?