Can you link to this grommet you refer to? Does the button physically click or is not even clicking unless you get it just right?
If the button doesn’t click, chances are what happened is that the bracket is either not aligned properly or it moved. Normally, I would apply a bead of two-part epoxy instead of superglue. The advantage is that you can do minor adjustments in the few minutes following application. After that, you have to let the glue set completely before applying too much pressure.
Always be careful with the Home Button, the flex is really easy to damage and as Nick notes in his comment, glue and electronics don’t always mix well. Closely inspect the HB to see if erratic glue or misalignment is the issue.