I just completed my monthly achievement for February by finishing an HotW run. I did not receive a notification of its completion or a completion chest. I did however receive 10 laurels in my inventory and I think some silver, but that’s it. When I check my character achievements the monthly is listed as 100% complete. So I’m short 45k karma’s worth of jugs, the 20 coins, and whatever other items I may have possibly gotten.
I’m guessing it’s a bug from potentially receiving two chests at the exact same moment. I just didn’t get the monthly one at all.