I have to forbid and claim any glowing spores if I want to trade them. Dormant spores don't have this issue. Edit: Scratch that, having the issue with both types of spores. Sorry if this is actually intentional somehow and I'm not understanding it correctly.
If the glowing spores drop near your town, they should be come automatically claimed. I suppose the problem is that they're not automatically forbidden, 'eh? Hmm, but they should be. Can you upload a saved game or screenshot showing the context in which these spores are appearing? Or heck, maybe more description? Everything *looks* correct in code to me, but I may be missing a key detail.
I only have a save about 15 days before it happened, and one a few days after. They came from a meteor event (not sure if they can occur any other way). I'll upload the file that's a few days after since I assume the one 2 weeks before won't help. They weren't auto forbidden I'm pretty sure. I'm not sure how the enemies generally work in terms of turning into cocoons or anything else, but there were a few that did that in my stockpiles if that's relevant. Also not sure when they leave the spores and such but I'm pretty sure I killed them all through normal combat. Sorry I can't be more helpful about the issue, I don't remember it clearly or have a convenient save for it. I'll keep an eye out next time I get a meteor event (save right before and pay more attention).
The save I posted here: https://community.gaslampgames.com/threads/stockpile-display-errors.18437/ Has a bunch of spores all over the place that everyone's ignoring. Selenians came at me three or four times, so the spores are starting to pile up...
Still trying to figure out the scripting system, but if it helps @dbaumgart, maybe its a tagging issue? Notice that the "glowing_spore" entity in commodity.edb has the "active_spore" tag, which is not used anywhere else I can find.
I don't know why it happens, but it only happens to spores that drop close enough to your colony to get claimed. The red 'forbidden' border doesn't show up, but for whatever reason they don't count as claimed. If you manually forbid and then claim them, they do count.
Found it! There was a particular objectcluster def for Selenian drops that wasn't flagged as player-owned. Fixed for experimental/next patch.