100% map completed, didn't receive reward
Go to the Deadend Waypoint in Bloodtide Coast, which is on Stormbluff Isle. It should pop up then and give you the rewards. You may have to walk inside the cave a little bit also.
I just completed Straights of Devestation and didn’t get a completion reward either. They always popped up regardless of where I was. I’ll check the update notes – maybe they did away with them?
You may officially call me an idiot. This was part of the new update that added waypoints to Straits – I had already done it (thought I did and was surprised to see it showing as one waypoint less than complete). I went back and got it but didn’t get the reward because I already got it, prior to the update. I got to lay off the Jack Daniels.