Philips Hue Wall Switch Module not working correctly

I have several Hue Wall switch modules. When they are configured as a dual-rocker the right button (as assigned from Phoscon) does not work reliably. At first I thought it was the light or the switch module itself. But I tried every possible combination and it’s always the right button that doesn’t work correctly. After adding and removing the rule several time it suddenly worked reliably. However I have recently added two more wall switch modules which exhibit the same problem. The right button does not work reliably. It works about 20% of the time. The left button works perfectly fine. I checked via the websockets api, it seems the events are not generated for the right button.