The bug

On a structure block, if you click the 2nd "Structure Integrity and Seed" box then the 1st one going backwards and upwards until you hit the "Structure Name" box, it will not de-select the original box that was selected. It happens whenever you click a box then another that was selected before that box. This only happens on Save mode and Load mode because they both have multiple boxes. Note: if you click the last one or one that is past the 2nd box then the box 2 behind from the first box you selected, then the one after the 2nd box you selected it will not de-select the 1st one you selected. Also, if you press "tab" then click a "type" box it will not select the "clickable" box. Note 2: If you press tab until it selects a clickable box then click the "next type" block it will not de-select the clickable box that was selected.

How to reproduce

1. Place a structure block and select it.
2. Go to load mode or save mode.
3. Click the last and bottom box and keep clicking the previous one before that.
4. Press "tab" until it selects a "clickable" box and do the previous step.
5. Another thing you can do is click "tab" until it selects a clickable box.
6. Click out the box and press "tab" once.

The cause

Look at each box and you will see all of them are selected and the next one will not de-select and if you start from the first going forward this won't happen.