Ok... so I found the issue in the code but I do not think it is easily fixable. It is only copying over the functions for the dimming part and not the on/off of the light. BUT, we can fix it manually (I think).
You will want this app, [RELEASE] Custom Device Note App
It is made to add custom notes to the "data" of a device but you can also edit/replace existing data.
On the LIGHT device, edit the "functions" data with that app and replace it with this:
{"light":{"type":"Boolean"},"bright_value":{"max":1000,"min":10,"scale":0,"step":1,"type":"Integer"}}
Thats it, should in theory work correctly now if I am understanding this right.
Looks like possibly, when the light is on, it is going to think the fan is also on. If that happens I see how we can fix that also by removing the "light" data from the functions on the fan device.