Weird leaking effect happening on my map for no reason.

Billo

aa
Feb 8, 2016
921
405
So, I was detailing sharkbay, i added roofs and stuff to many buildings so there are not flat anymore and I added some details as well, i thought this area close to the spawn needs to have a fence overlooking outside to give it a feel of depth. I run the game but i notice the skybox leaks BUT only in one angle. 20190111142643_1.jpg 20190111142646_1.jpg
I tried experiementing a bit.
I tried remaking the skybox around this area , to check for any leaks on my own , used interlopers site to make sure my compile log doesnt have any errors etc. But hammer says that there are no leaks.
I noticed that the error happens only when you looked at the fence so i deleted it but still nothing.
here is a picture in hammer:
leak.PNG
it's the first time i face such a weird problem and I honestly have no Idea what could be causing it.
 

Billo

aa
Feb 8, 2016
921
405
Update: the only progress i made is that when I removed the 3d skybox entirely the leak gets fixed. does that ring any bells?