In 2010 hiking in Pennsylvania I had just that problem. I tried all sorts of solutions including duct tape. Nothing seemed to help.
Then I remembered on a hike in the Wind River Range another hiker cut away part of an inner sole to relieve pressure on a blister. I decided nothing else has worked so let's try it.
I cut a sort of half moon out where the inner sole rubbed against the inflamed area. Relief came quickly. It worked sort of like a moleskin donut around a blister.
The best time to make this modification is at the first sign of trouble. Once a blister forms here, it will take a while to heal.