Bonus assignment reward erases fragment progress
I guess this is not technically considered a bug, but with the way the rewards are set up for the brilliant event it erases any fragments you had collected from portkeys if you tap on the final rewards button before placing your registry image. For example, on brilliant baby beasts part 2 I had 2 giant squid fragments. I completed the bonus assignment and collected the reward of 5 fragments, but the counter read 5/5 and when I placed the images it reset to 0/5. The two fragments I had collected disappeared.