in the PRC recipe GUI, it seems like the mouseover regions do not match the GUI. Substrate and Biofuel seem to work, but the other regions do not seem to match. They seem to be shifted down and to the right.

To see the effect, open the PRC GUI, then click on the Recipes arrow. If you mouseover the top-left corner of water, ethylene, hydrogen, etc., no text will show. If you mouseover the lower-right corner, you will see the text.

Don't know how I missed that. Fixed!