Conditional formatting based on a range

Hello

English is not my first language, so I've included an picture

to make my question hopefully more clear.

I am trying to make a auto gantt chart in excel. I use start date and end date, and then convert these to their numerical values in two other cells.

I then make some condtional formatting rules to colour the right amount of cells based on these two values. For some reason it wont colour the correct cells when applied to other rows. Do I need to do some VB shenanigans to make this work? For some reason it works sporadically. Maybe its something simple that I haven't seen. I update the formular in each cell to include the "right range"

Thanks in advance