Yes I know there is another invisible webs bug so this may be related but it is not the same one.
Bug I have encountered is slightly different.
The bug has only occured on combat maps, in NS maps i haven't had it happen.
As gorge, (without flashlight on) when placing webs the webs have been invisible, except for the first web I have placed. At the time I have had all upgrades and have been on a server with extralevels (But not extra upgrades like cybernetics etc) if that is relevant at all.
It has occured on both custom and non-custom maps.
If I die and re-evolve to gorge they are still invisible. If I die and evolve to something else they become visible.