You’re not wrong.
Up until a few days ago we had several powers that would randomly drop off as you progressed in to runs. Meaning you could have 4 stacks of Unceasing Chain Link drop down to only 1. 450% damage loss on that particular power.
Other powers known to be affected included Leather Apron, Shadowguard Armaments, Prisim Shawl, and a few others.
In one of my runs with a group on Floor 12 I had 70 powers. By the time we got to floor 18 (Killing everything along the way) I had 68. We climbed 6 floors for me to be down 2 powers.
From testing it seems UCL has been fixed but several others are still broken: Torghast, Unceasing chain link anima