I pick my User Story, and try to 'Move' it.
The "Parent Issue" field allows me to type a string in there, and it indeed shows me the task I want to re-parent to.
However, it doesn't let me select it, and fill in the field. I click many many times on the option it gives me, but it doesn't let me pick it.
If I click 'Select issue', it only gives me the last 4 issues I looked at, and doesn't let me enter anything else.
... maddening...