I found an interesting enough bug
after generating the shop bug where you can only use a trading depot the first time you see it then after you leave and come back you can't go there again
I retired at the fortress(has both dwarves and goblins and is called dwarven) and then continued the same guy, so he was only retired for ~15 days at the fortress; when I came back the fortress had a completely different layout the elf bird corpses were still at the entrance of the mountain tunnels(they were there when i retired) and the mountain tunnels were partially redesigned too with a 3x3 hole in the center of the start of them leading down to the new redesigned fortress
to my suprise, in the trade depot, it wasn't much different with the old table with items there on the left side, except that now it was devoid of people and there was a new place north of the center area of the trade depot without a table; all the people who would normally be at the original table were instead there, without a table, and there was a whole new batch of stuff without a table blocking its ability to be picked up, and they had $$ signs around them too; however there were some items outside of the 5x5 area where the items should've normally egnerated if a new npc trade depot was designated and I couldn't trade for those items unless I picked them up manually and dropped them in the 5x5 area where the table would've been if there was one
on an unrelated note before I retired there was a curious sight; a goblin recruit going up the fortress' stairs, saying he is "on an important mission"; he later went outside of the fortress, maybe a screen or two to the east of the trade depot, and he has some buddies who don't move from there
after this I left for a whole killed two alligators and came back with meat, and now all of the NPCs are back at the original
later I left and came back and on the way back to the fortress I saw those same goblins i mentioned earlier, except now theres some scattered campfires(I never placed any) around them; I'm thinking they're setting up a bandit camp or trying to do something bad to the dwarven civ or something, but the mayor of the fortress is a goblin so I don't know
allegedly, this guy is still on an "important mission"
when i got back to the fortress all the guys from the new northen trading non-table were gone and at the eastern trading table that was originally there again, and is still bugged and was not replenished with new loot; as well the fortress was redesgined, AGAIN, including the tunnel, back to the form it was in before I retired for 15 days or so
all of the loot from the new trading non-table is still there, and all the dollar signs around it dissapeared, but unlike the oirignal trading table I can actually pick all of these up, woohoo free stuff!
EDIT: I reexplored the fortress and found a goblin with the title of "chief medical dwarf" and the tile isn't glowing or anything; this place is weird, though I might've just missed im the first time around
EDIT EDIT: now I went down the tunnels to the other fortress and learned that the queen is a goblin; I told her that I commited a robbery and she just said, it was inevitable
i dont think the game actually considered it to be a robbery though; I was just picking up items that lost their $tags$ due to a horrible,terrible bug, and keeping them
at least I can work around the only use a trade depot once bug by buying and selling what i buy then buying something else then selling that and buying something else till the whole inventory has had that done to it, then coming back later and getting everything for free, which makes the stuff be above the table instead of underneath it, and allows it to be picked up