Guaranteed Waystone Not Always Dropping(Mansion in the Mists)

It usually does. I thought I was going crazy when I returned from a map and had no waystones. This last example was a delirium map with no other modifiers. I had no deaths, finished the last rare, clicked the hengestone that appeared, and there was no waystone from the final rare.

Edit: It is levels nearby Mansion in the Mists, which has other problems. First, you have clear some junk levels to get to the swirly level. Sometimes a hengestone appears in these levels anyways. I cleared 3 hengestones including the swirly level, and it "uncleared" a level which I then did and clicked a hengestone, then it "uncleared" another level which gave a hengestone. STILL NO ENTRANCE TO THE MANSION. And all these levels are *not* dropping waystones on completion. The swirly part on the atlas is now on the Mansion, all zones around it are cleared and keep reopening 1 at a time to reveal hengestones.

5 hengestones, repeating maps, getting no guaranteed waystone, and never getting an entrance to the Mansion.