I have run across this issue in the last several versions of 4space on multiple versions of forge and even in both java 7 and 8. This is using Galacticraft 1.7-18.104.22.1683
Originally I thought some of these issues were due to mod conflicts as I was running a large number of mods including multiple addons for Galacticraft but I have been able to reproduce them on a fresh install with just forge, galacticraft and 4space installed.
First issue, it seems your new solar system map is rendering underneath the main map so if I scroll up to it, it disappears behind the Galacticraft Map:
If I continue to scroll up your new solar system disappears all together.
Second Issue, Clicking on the star of the new solar system zooms me onto Sol instead of Gliese 581G.
Third Issue, attempting to click on any of the exo planets and zooming in brings me to either a completely empty view or a view where I can see the orbit rings of the moon(s) around the planet but not the planet or moons themselves.
Now I can click on Elpis without zooming in and thus can launch to it,but if there are actually any moons around the other 3 exoplanets, I cannot see them.
I am not sure if there is a bug or if you are aware of this issue and I apologize if you are.