Since you are below 940, your pinnacle reward would have been +5 of whatever your base power is, which looks to have been around 906-907 at the time. If you got a 911 or 912 item from the activity, that was your pinnacle reward. Otherwise keep in mind sometimes items that go straight to your inventory might not flash, so check all your slots for a higher power item and also be sure to check your Postmaster if any slots are full.
It’s probably bugged until they put the patch through... it wouldn’t surprise me. Most players are not completing those milestones until the weekend.