I don’t know if it will work for anyone else, but I had the same issue where I had the cog and Rikka wouldn’t talk to me about the rag. I went back to the starting NPC, Terksli, clicked through the dialogue again, went back to Rikka, and then it was fine. For the golem I tried killing him repeatedly, then gave up for a while and when I tried again after the daily reset it worked.
GW2 is weird with achievements/quests lately. -_ (o.o) _-
“Dovie’andi se tovya sagain.”