Lighting zoom dependend?

all the lighting vanishes if i zoom out, come back on zoom in.
Feature or bug?

@stevebaer or @DavidEranen, something for either of you?

Hi Stephan,

What GPU and driver version are you using? Do you think it would be possible for you to share the file?

and here is a zip file with the plugin and sample mesh:
to see the faulty behaviour:
start rhino6
install the plugin
load the 3dm file
execute RREditGrid
zoom out/in

plguin and 3dm file are here: