I tried to reproduce your problem and I got the expected results; the value for the cell with the name AI appeared when I entered the formula
If you're getting the #NAME? error, it most likely means that there is no cell or range of cells with the name AI.
This can be easily resolved by ensuring there is a valid cell/range with the name.
If you still have the problem, try naming your cell to something that actually represents the content of the cell. If that is not possible, append an underscore to the name (
AI_) and use it in your formula.