I have noticed that I cannot manually type into the speed box within the Layer/Timing window. I can use the slider to adjust the speed and the preview does update. Once I click save, the speed reverts back to a faster setting within the preview window (twinkle effect), yet the slider and numerical value remains where it was set.
I also noticed that if you click on the Morph check box under blending (layer/timing window), click into another effect within the grid, then click back to the previous effect, the Morph check box is no longer checked.
xLights 4.0.14 running on Mac OS X