Last night I earned the achievement for Specialist Contributor IV, and have tried to collect the Legendary Soul over 10 times, and continue to get the below error.
Android OS / Samsung Galaxy S8.
Steps taken to duplicate:
Go to achievements. Click "claim" and it does the animation.
Click the arrow to back out of achievements, or click on another achievement (Go CTA) and I get:
NOTICE:
"An error has occurred, daily challenge changes were not saved."
Then...
Server Timeout - Unable to retrieve response from the server. Restart in 5...4... etc. and it restarts the game.
And it looks like it's happening even if I don't claim the achievement.