I realize you said you went from 1-4 today. But you might find it helpful to read through Josh’s full post a little while back for a bit of added context.
I think their design is that you can only revert to the immediate prior released version. (They likely designed from the perspective that you would consistently move from 1 to 2, 2 to 3, etc, not multiple versions).
If you temporarily need to go back to the old version – for instance, if you haven’t finished testing the new Bubble version, but something comes up and you need to do an urgent deploy to Live – you can use the Versions tab to roll back to the old version. (The option to revert will disappear after a week on the new version.)