The Underpin not dropping map

Second week in a row where The Underpin doesn’t drop a map for the 649 chest at the end. Before I entered the delve, it had the map listed under Lost Keepsakes. I used the Wave Scrambler 2000 to summon him.
After defeating him, the map was not in the pile of loot. When I tried to enter a new delve, the map was removed as a potential reward. So the game has somehow registered that I got the reward, but it’s not in my inventory. I also wasted 2000 undercoins on a wave scrambler.

I had already defeated The Underpin on a different character yesterday, but unless it’s somehow been stealth nerfed to only give one map pr week on your account, this is clearly bugged and needs to be fixed.

Well the map was never guaranteed drop - just like zekvir of spwned didnt nessesarily gave you map .

And yes Blizzard fixed it to 1 map per character per week.

This is the character I used the Wave Scrambler with. You can clearly see that the game considers that I have gotten the Delver’s Bounty for the week, as it is removed as a potential reward.

This is a different character which hasn’t done any delves this week, so the Delver’s Bounty is shown as a potential reward. Normally, this is only removed once your character has gotten their 1 drop for the week.

Also, every time I’ve fought The Underpin, he has dropped a Delver’s Bounty after, and also stopped spawning for the rest of the week. I ran like 15x Tier 11 delves on my DK one week to farm crests, and I only had a single Underpin spawn.

Every other character where I fought Underpin, he dropped a Delver’s Bounty on the first encounter with them, regardless if spawned randomly or was summoned with a Wave Scrambler.
I don’t have any other explanation that this is a bug. It happened two weeks in a row on my druid, where I used the Wave Scrambler to summon The Underpin.