Could be that this New Year thing has something to do with that. Also, it seems that after you edited the post, the .blend attachment link got corrupted (only accessible from the original version of the post).
If I understand correctly what you want to do, then it’s this, starting with that .blend file:
- Switch pivot to Median Point
- Switch to top view
- Box-select all vertices on the left side of the object and scale them to 0 on X axis
- Box-select all vertices on the right side of the object and scale them to 0 on X axis
- Select everything and input 1 into the Median X location field.
Simply moving every face individually will not achieve desired result as specified: moving one face will also move vertices of adjacent faces, which will then make their median not be at 1.