Random node breaks lighting each time the level is loaded

Hi, I’m sorry if this has been asked before but I can’t find anything about this problem.

I have a simple blueprint that creates a row of instanced folders. They are slightly transformed and rotated through random values. When I build lighting the folders have their lighting correctly built. They are set to “static”. - But when I close the level and reopen it, the randomness seems to be re-triggered so the folders loose their lighting data and are unlit.

What is the best way to solve this? Can I freeze the Random Integer node? When does it actually update? Below are images of the blueprint (construction script) and the folder with lighting built. There is nothing in the Event Graph.

Thanks in advance.

I figured it out myself. I had to use the “Random Float from Stream” and not the “Random Float”.